1
|
Khramova YV, Katrukha VA, Chebanenko VV, Kostyuk AI, Gorbunov NP, Panasenko OM, Sokolov AV, Bilan DS. Reactive Halogen Species: Role in Living Systems and Current Research Approaches. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:S90-S111. [PMID: 38621746 DOI: 10.1134/s0006297924140062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/21/2023] [Accepted: 10/04/2023] [Indexed: 04/17/2024]
Abstract
Reactive halogen species (RHS) are highly reactive compounds that are normally required for regulation of immune response, inflammatory reactions, enzyme function, etc. At the same time, hyperproduction of highly reactive compounds leads to the development of various socially significant diseases - asthma, pulmonary hypertension, oncological and neurodegenerative diseases, retinopathy, and many others. The main sources of (pseudo)hypohalous acids are enzymes from the family of heme peroxidases - myeloperoxidase, lactoperoxidase, eosinophil peroxidase, and thyroid peroxidase. Main targets of these compounds are proteins and peptides, primarily methionine and cysteine residues. Due to the short lifetime, detection of RHS can be difficult. The most common approach is detection of myeloperoxidase, which is thought to reflect the amount of RHS produced, but these methods are indirect, and the results are often contradictory. The most promising approaches seem to be those that provide direct registration of highly reactive compounds themselves or products of their interaction with components of living cells, such as fluorescent dyes. However, even such methods have a number of limitations and can often be applied mainly for in vitro studies with cell culture. Detection of reactive halogen species in living organisms in real time is a particularly acute issue. The present review is devoted to RHS, their characteristics, chemical properties, peculiarities of interaction with components of living cells, and methods of their detection in living systems. Special attention is paid to the genetically encoded tools, which have been introduced recently and allow avoiding a number of difficulties when working with living systems.
Collapse
Affiliation(s)
- Yuliya V Khramova
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | - Veronika A Katrukha
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | - Victoria V Chebanenko
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | - Alexander I Kostyuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Moscow, 117997, Russia
| | | | - Oleg M Panasenko
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Alexey V Sokolov
- Institute of Experimental Medicine, Saint-Petersburg, 197022, Russia.
- Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Dmitry S Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia.
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Moscow, 117997, Russia
| |
Collapse
|
2
|
Melnik BS, Glukhova KA, Sokolova (Voronova) EA, Balalaeva IV, Garbuzynskiy SO, Finkelstein AV. Physics of Ice Nucleation and Antinucleation: Action of Ice-Binding Proteins. Biomolecules 2023; 14:54. [PMID: 38254654 PMCID: PMC10813080 DOI: 10.3390/biom14010054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/09/2023] [Accepted: 12/27/2023] [Indexed: 01/24/2024] Open
Abstract
Ice-binding proteins are crucial for the adaptation of various organisms to low temperatures. Some of these, called antifreeze proteins, are usually thought to inhibit growth and/or recrystallization of ice crystals. However, prior to these events, ice must somehow appear in the organism, either coming from outside or forming inside it through the nucleation process. Unlike most other works, our paper is focused on ice nucleation and not on the behavior of the already-nucleated ice, its growth, etc. The nucleation kinetics is studied both theoretically and experimentally. In the theoretical section, special attention is paid to surfaces that bind ice stronger than water and thus can be "ice nucleators", potent or relatively weak; but without them, ice cannot be nucleated in any way in calm water at temperatures above -30 °C. For experimental studies, we used: (i) the ice-binding protein mIBP83, which is a previously constructed mutant of a spruce budworm Choristoneura fumiferana antifreeze protein, and (ii) a hyperactive ice-binding antifreeze protein, RmAFP1, from a longhorn beetle Rhagium mordax. We have shown that RmAFP1 (but not mIBP83) definitely decreased the ice nucleation temperature of water in test tubes (where ice originates at much higher temperatures than in bulk water and thus the process is affected by some ice-nucleating surfaces) and, most importantly, that both of the studied ice-binding proteins significantly decreased the ice nucleation temperature that had been significantly raised in the presence of potent ice nucleators (CuO powder and ice-nucleating bacteria Pseudomonas syringae). Additional experiments on human cells have shown that mIBP83 is concentrated in some cell regions of the cooled cells. Thus, the ice-binding protein interacts not only with ice, but also with other sites that act or potentially may act as ice nucleators. Such ice-preventing interaction may be the crucial biological task of ice-binding proteins.
Collapse
Affiliation(s)
- Bogdan S. Melnik
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia; (K.A.G.); (S.O.G.)
| | - Ksenia A. Glukhova
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia; (K.A.G.); (S.O.G.)
| | - Evgeniya A. Sokolova (Voronova)
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 603022 Nizhny Novgorod, Russia (I.V.B.)
| | - Irina V. Balalaeva
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 603022 Nizhny Novgorod, Russia (I.V.B.)
| | - Sergiy O. Garbuzynskiy
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia; (K.A.G.); (S.O.G.)
| | - Alexei V. Finkelstein
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia; (K.A.G.); (S.O.G.)
- Faculty of Biotechnology, Lomonosov Moscow State University, 142290 Pushchino, Russia
- Faculty of Biology, Lomonosov Moscow State University, 119192 Moscow, Russia
| |
Collapse
|
3
|
Son A, Huizar Cabral V, Huang Z, Litberg TJ, Horowitz S. G-quadruplexes rescuing protein folding. Proc Natl Acad Sci U S A 2023; 120:e2216308120. [PMID: 37155907 PMCID: PMC10194009 DOI: 10.1073/pnas.2216308120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 04/12/2023] [Indexed: 05/10/2023] Open
Abstract
Maintaining the health of the proteome is a critical cellular task. Recently, we found G-quadruplex (G4) nucleic acids are especially potent at preventing protein aggregation in vitro and could at least indirectly improve the protein folding environment of Escherichia coli. However, the roles of G4s in protein folding were not yet explored. Here, through in vitro protein folding experiments, we discover that G4s can accelerate protein folding by rescuing kinetically trapped intermediates to both native and near-native folded states. Time-course folding experiments in E. coli further demonstrate that these G4s primarily improve protein folding quality in E. coli as opposed to preventing protein aggregation. The ability of a short nucleic acid to rescue protein folding opens up the possibility of nucleic acids and ATP-independent chaperones to play considerable roles in dictating the ultimate folding fate of proteins.
Collapse
Affiliation(s)
- Ahyun Son
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
| | - Veronica Huizar Cabral
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
| | - Zijue Huang
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
| | - Theodore J. Litberg
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
| | - Scott Horowitz
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
| |
Collapse
|
4
|
Low protein expression enhances phenotypic evolvability by intensifying selection on folding stability. Nat Ecol Evol 2022; 6:1155-1164. [PMID: 35798838 PMCID: PMC7613228 DOI: 10.1038/s41559-022-01797-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 05/19/2022] [Indexed: 01/09/2023]
Abstract
Protein abundance affects the evolution of protein genotypes, but we do not know how it affects the evolution of protein phenotypes. Here we investigate the role of protein abundance in the evolvability of green fluorescent protein (GFP) towards the novel phenotype of cyan fluorescence. We evolve GFP in E. coli through multiple cycles of mutation and selection and show that low GFP expression facilitates the evolution of cyan fluorescence. A computational model whose predictions we test experimentally helps explain why: lowly expressed proteins are under stronger selection for proper folding, which facilitates their evolvability on short evolutionary time scales. The reason is that high fluorescence can be achieved by either few proteins that fold well or by many proteins that fold less well. In other words, we observe a synergy between a protein's scarcity and its stability. Because many proteins meet the essential requirements for this scarcity-stability synergy, it may be a widespread mechanism by which low expression helps proteins evolve new phenotypes and functions.
Collapse
|
5
|
Abstract
Abstract
Antifreeze proteins, expressed in cold-blooded organisms, prevent ice formation in their bodies, and thus help them to survive in extremely cold winter temperatures. However, the mechanism of action of these proteins is still not clear. In any case, it is not simply a decrease in the temperature of normal ice formation. In this work, investigating the ice-binding protein (a mutant form of the antifreeze protein cfAFP from the spruce budworm Choristoneura fumiferana, which overwinters in needles), we showed that this antifreeze protein does not at all lower the freezing point of water and, paradoxically, increases the melting point of ice. On the other hand, calculations based on the theory of crystallization show that at temperatures of 0 ° to –30°C ice can only appear on surfaces that contact water, but not in the body of water. These facts suggest a new perspective on the role of antifreeze proteins: their task is not (as it is commonly believed) to bind with nascent ice crystals already formed in the organism and stop their growth, but to bind to those surfaces, on which ice nuclei can appear, and thus completely inhibit the ice formation in supercooled water or biological fluid.
Collapse
|
6
|
Deeva AA, Glukhova KA, Isoyan LS, Okulova YD, Uversky VN, Melnik BS. Design and Analysis of a Mutant form of the Ice-Binding Protein from Choristoneura fumiferana. Protein J 2022; 41:304-314. [PMID: 35366124 DOI: 10.1007/s10930-022-10049-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2022] [Indexed: 10/18/2022]
Abstract
Ice-binding proteins are expressed in the cells of some cold adapted organisms, helping them to survive at extremely low temperatures. One of the problems in studying such proteins is the difficulty of their isolation and purification. For example, eight cysteine residues in the cfAF (antifreeze protein from the eastern spruce budworm Choristoneura fumiferana) form intermolecular bridges during the overexpression of this protein. This impedes the process of the protein purification dramatically. To overcome this issue, in this work, we designed a mutant form of the ice-binding protein cfAFP, which is much easier to isolate that the wild-type protein. The mutant form named mIBP83 did not lose the ability to bind to ice surface. Besides, observation of the processes of freezing and melting of ice in the presence of mIBP83 showed that this protein affects the process of ice melting, increasing its melting temperature, and does not decrease the water freezing temperature.
Collapse
Affiliation(s)
- Anna A Deeva
- Biophysics Department, Siberian Federal University, Svobodny 79, Krasnoyarsk, Russia, 660041
| | - Ksenia A Glukhova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Puschino, Russia
| | - Lala S Isoyan
- Biophysics Department, Siberian Federal University, Svobodny 79, Krasnoyarsk, Russia, 660041
| | - Yuliya D Okulova
- Institute of Protein Research of the Russian Academy of Sciences, 4 Institutskaya Str., Pushchino, Moscow Region, Russia, 142290
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institure, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Bogdan S Melnik
- Institute of Protein Research of the Russian Academy of Sciences, 4 Institutskaya Str., Pushchino, Moscow Region, Russia, 142290.
| |
Collapse
|
7
|
Song H, Wang Y, Dong W, Chen Q, Sun H, Peng H, Li R, Chang Y, Luo H. Effect of SpyTag/SpyCatcher cyclization on stability and refolding of green fluorescent protein. Biotechnol Lett 2022; 44:613-621. [PMID: 35359178 DOI: 10.1007/s10529-022-03246-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/15/2022] [Indexed: 11/26/2022]
Abstract
To study the effect of SpyTag/SpyCatcher cyclization on stability and refolding of protein, we constructed a cyclized green fluorescent protein (SRGFP) and its derivative to act as a linear structure control (L-SRGFP). SRGFP and L-SRGFP showed similar fluorescence characteristics to the wild-type GFP, while compared with GFP and L-SRGFP, the thermal stability and denaturation resistance of SRGFP were improved. The refolding efficiencies of these three denatured proteins were investigated under different pH, temperature and initial protein concentration conditions, and it was found that SRGFP was superior to GFP and L-SRGFP in terms of refolding yield and refolding speed. In the pH range of 8.0-8.5, SRGFP could basically recover all fluorescence, while GFP and L-SRGFP recovered only about 87.52% and 88.58%. When refolded at a high temperature (37 °C), SRGFP still recovered 85.27% of the fluorescence, whereas GFP and L-SRGFP recovered only around 69.43% and 68.45%. At a high initial protein concentration (5 mg/mL), the refolding yield of SRGFP was about 15% higher than that of both GFP and L-SRGFP. These results suggest that the introduction of SpyRing structure (head-to-tail cyclization via SpyTag and SpyCatcher) improved the protein's stability and facilitated the refolding of denatured protein.
Collapse
Affiliation(s)
- Haiyan Song
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Yue Wang
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Wenge Dong
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Qiwei Chen
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Hongxu Sun
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Hui Peng
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Ren Li
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Yanhong Chang
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China.
| | - Hui Luo
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
| |
Collapse
|
8
|
Ithurbide S, Gribaldo S, Albers SV, Pende N. Spotlight on FtsZ-based cell division in Archaea. Trends Microbiol 2022; 30:665-678. [PMID: 35246355 DOI: 10.1016/j.tim.2022.01.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 12/22/2021] [Accepted: 01/10/2022] [Indexed: 12/15/2022]
Abstract
Compared with the extensive knowledge on cell division in model eukaryotes and bacteria, little is known about how archaea divide. Interestingly, both endosomal sorting complex required for transport (ESCRT)-based and FtsZ-based cell division systems are found in members of the Archaea. In the past couple of years, several studies have started to shed light on FtsZ-based cell division processes in members of the Euryarchaeota. In this review we highlight recent findings in this emerging field of research. We present current knowledge of the cell division machinery of halophiles which relies on two FtsZ proteins, and we compare it with that of methanobacteria, which relies on only one FtsZ. Finally, we discuss how these differences relate to the distinct cell envelopes of these two archaeal model systems.
Collapse
Affiliation(s)
- Solenne Ithurbide
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Simonetta Gribaldo
- Evolutionary Biology of the Microbial Cell Unit, CNRS UMR2001, Department of Microbiology, Institut Pasteur, Paris, France.
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany.
| | - Nika Pende
- Evolutionary Biology of the Microbial Cell Unit, CNRS UMR2001, Department of Microbiology, Institut Pasteur, Paris, France
| |
Collapse
|
9
|
Perach M, Zafrir Z, Tuller T, Lewinson O. Identification of conserved slow codons that are important for protein expression and function. RNA Biol 2021; 18:2296-2307. [PMID: 33691590 PMCID: PMC8632084 DOI: 10.1080/15476286.2021.1901185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 02/28/2021] [Accepted: 03/06/2021] [Indexed: 10/21/2022] Open
Abstract
ABSTRASTDue to the redundancy of the genetic code most amino acids are encoded by several 'synonymous' codons. These codons are used unevenly, and each organism demonstrates its own unique codon usage bias, where the 'preferred' codons are associated with tRNAs that are found in high concentrations. Therefore, for decades, the prevailing view had been that preferred and non-preferred codons are linked to high or slow translation rates, respectively.However, this simplified view is contrasted by the frequent failures of codon-optimization efforts and by evidence of non-preferred (i.e. 'slow') codons having specific roles important for efficient production of functional proteins. One such specific role of slower codons is the regulation of co-translational protein folding, a complex biophysical process that is very challenging to model or to measure.Here, we combined a genome-wide approach with experiments to investigate the role of slow codons in protein production and co-translational folding. We analysed homologous gene groups from divergent bacteria and identified positions of inter-species conservation of bias towards slow codons. We then generated mutants where the conserved slow codons are substituted with 'fast' ones, and experimentally studied the effects of these codon substitutions. Using cellular and biochemical approaches we find that at certain locations, slow-to-fast codon substitutions reduce protein expression, increase protein aggregation, and impair protein function.This report provides an approach for identifying functionally relevant regions with slower codons and demonstrates that such codons are important for protein expression and function.
Collapse
Affiliation(s)
- Michal Perach
- Department of Molecular Microbiology, the Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, Haifa, Israel
| | - Zohar Zafrir
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Tamir Tuller
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Oded Lewinson
- Department of Molecular Microbiology, the Bruce and Ruth Rappaport Faculty of Medicine, The Technion-Israel Institute of Technology, Haifa, Israel
| |
Collapse
|
10
|
Sulatskaya AI, Kosolapova AO, Bobylev AG, Belousov MV, Antonets KS, Sulatsky MI, Kuznetsova IM, Turoverov KK, Stepanenko OV, Nizhnikov AA. β-Barrels and Amyloids: Structural Transitions, Biological Functions, and Pathogenesis. Int J Mol Sci 2021; 22:11316. [PMID: 34768745 PMCID: PMC8582884 DOI: 10.3390/ijms222111316] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 01/17/2023] Open
Abstract
Insoluble protein aggregates with fibrillar morphology called amyloids and β-barrel proteins both share a β-sheet-rich structure. Correctly folded β-barrel proteins can not only function in monomeric (dimeric) form, but also tend to interact with one another-followed, in several cases, by formation of higher order oligomers or even aggregates. In recent years, findings proving that β-barrel proteins can adopt cross-β amyloid folds have emerged. Different β-barrel proteins were shown to form amyloid fibrils in vitro. The formation of functional amyloids in vivo by β-barrel proteins for which the amyloid state is native was also discovered. In particular, several prokaryotic and eukaryotic proteins with β-barrel domains were demonstrated to form amyloids in vivo, where they participate in interspecies interactions and nutrient storage, respectively. According to recent observations, despite the variety of primary structures of amyloid-forming proteins, most of them can adopt a conformational state with the β-barrel topology. This state can be intermediate on the pathway of fibrillogenesis ("on-pathway state"), or can be formed as a result of an alternative assembly of partially unfolded monomers ("off-pathway state"). The β-barrel oligomers formed by amyloid proteins possess toxicity, and are likely to be involved in the development of amyloidoses, thus representing promising targets for potential therapy of these incurable diseases. Considering rapidly growing discoveries of the amyloid-forming β-barrels, we may suggest that their real number and diversity of functions are significantly higher than identified to date, and represent only "the tip of the iceberg". Here, we summarize the data on the amyloid-forming β-barrel proteins, their physicochemical properties, and their biological functions, and discuss probable means and consequences of the amyloidogenesis of these proteins, along with structural relationships between these two widespread types of β-folds.
Collapse
Affiliation(s)
- Anna I. Sulatskaya
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, 3 Podbelskogo Sh., Pushkin, 196608 St. Petersburg, Russia; (A.I.S.); (A.O.K.); (M.V.B.); (K.S.A.)
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Av., 194064 St. Petersburg, Russia; (I.M.K.); (K.K.T.); (O.V.S.)
| | - Anastasiia O. Kosolapova
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, 3 Podbelskogo Sh., Pushkin, 196608 St. Petersburg, Russia; (A.I.S.); (A.O.K.); (M.V.B.); (K.S.A.)
- Faculty of Biology, St. Petersburg State University, 7/9 Universitetskaya Emb., 199034 St. Petersburg, Russia
| | - Alexander G. Bobylev
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 3 Institutskaya St., 142290 Moscow, Russia;
| | - Mikhail V. Belousov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, 3 Podbelskogo Sh., Pushkin, 196608 St. Petersburg, Russia; (A.I.S.); (A.O.K.); (M.V.B.); (K.S.A.)
- Faculty of Biology, St. Petersburg State University, 7/9 Universitetskaya Emb., 199034 St. Petersburg, Russia
| | - Kirill S. Antonets
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, 3 Podbelskogo Sh., Pushkin, 196608 St. Petersburg, Russia; (A.I.S.); (A.O.K.); (M.V.B.); (K.S.A.)
- Faculty of Biology, St. Petersburg State University, 7/9 Universitetskaya Emb., 199034 St. Petersburg, Russia
| | - Maksim I. Sulatsky
- Laboratory of Cell Morphology, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Av., 194064 St. Petersburg, Russia;
| | - Irina M. Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Av., 194064 St. Petersburg, Russia; (I.M.K.); (K.K.T.); (O.V.S.)
| | - Konstantin K. Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Av., 194064 St. Petersburg, Russia; (I.M.K.); (K.K.T.); (O.V.S.)
| | - Olesya V. Stepanenko
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Av., 194064 St. Petersburg, Russia; (I.M.K.); (K.K.T.); (O.V.S.)
| | - Anton A. Nizhnikov
- Laboratory for Proteomics of Supra-Organismal Systems, All-Russia Research Institute for Agricultural Microbiology, 3 Podbelskogo Sh., Pushkin, 196608 St. Petersburg, Russia; (A.I.S.); (A.O.K.); (M.V.B.); (K.S.A.)
- Faculty of Biology, St. Petersburg State University, 7/9 Universitetskaya Emb., 199034 St. Petersburg, Russia
| |
Collapse
|
11
|
A general approach to protein folding using thermostable exoshells. Nat Commun 2021; 12:5720. [PMID: 34588451 PMCID: PMC8481291 DOI: 10.1038/s41467-021-25996-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 09/07/2021] [Indexed: 02/08/2023] Open
Abstract
In vitro protein folding is a complex process which often results in protein aggregation, low yields and low specific activity. Here we report the use of nanoscale exoshells (tES) to provide complementary nanoenvironments for the folding and release of 12 highly diverse protein substrates ranging from small protein toxins to human albumin, a dimeric protein (alkaline phosphatase), a trimeric ion channel (Omp2a) and the tetrameric tumor suppressor, p53. These proteins represent a unique diversity in size, volume, disulfide linkages, isoelectric point and multi versus monomeric nature of their functional units. Protein encapsulation within tES increased crude soluble yield (3-fold to >100-fold), functional yield (2-fold to >100-fold) and specific activity (3-fold to >100-fold) for all the proteins tested. The average soluble yield was 6.5 mg/100 mg of tES with charge complementation between the tES internal cavity and the protein substrate being the primary determinant of functional folding. Our results confirm the importance of nanoscale electrostatic effects and provide a solution for folding proteins in vitro.
Collapse
|
12
|
Nguyen KT, Sugie J, Khanna K, Egan ME, Birkholz EA, Lee J, Beierschmitt C, Villa E, Pogliano J. Selective transport of fluorescent proteins into the phage nucleus. PLoS One 2021; 16:e0251429. [PMID: 34111132 PMCID: PMC8191949 DOI: 10.1371/journal.pone.0251429] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/26/2021] [Indexed: 11/18/2022] Open
Abstract
Upon infection of Pseudomonas cells, jumbo phages 201Φ2-1, ΦPA3, and ΦKZ assemble a phage nucleus. Viral DNA is enclosed within the phage-encoded proteinaceous shell along with proteins associated with DNA replication, recombination and transcription. Ribosomes and proteins involved in metabolic processes are excluded from the nucleus. RNA synthesis occurs inside the phage nucleus and messenger RNA is presumably transported into the cytoplasm to be translated. Newly synthesized proteins either remain in the cytoplasm or specifically translocate into the nucleus. The molecular mechanisms governing selective protein sorting and nuclear import in these phage infection systems are currently unclear. To gain insight into this process, we studied the localization of five reporter fluorescent proteins (GFP+, sfGFP, GFPmut1, mCherry, CFP). During infection with ΦPA3 or 201Φ2-1, all five fluorescent proteins were excluded from the nucleus as expected; however, we have discovered an anomaly with the ΦKZ nuclear transport system. The fluorescent protein GFPmut1, expressed by itself, was transported into the ΦKZ phage nucleus. We identified the amino acid residues on the surface of GFPmut1 required for nuclear targeting. Fusing GFPmut1 to any protein, including proteins that normally reside in the cytoplasm, resulted in transport of the fusion into the nucleus. Although the mechanism of transport is still unknown, we demonstrate that GFPmut1 is a useful tool that can be used for fluorescent labelling and targeting of proteins into the ΦKZ phage nucleus.
Collapse
Affiliation(s)
- Katrina T Nguyen
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Joseph Sugie
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Kanika Khanna
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - MacKennon E Egan
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Erica A Birkholz
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Jina Lee
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Christopher Beierschmitt
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Elizabeth Villa
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Joe Pogliano
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| |
Collapse
|
13
|
Electrophoretic Mobility Shift Assays with GFP-Tagged Proteins (GFP-EMSA). Methods Mol Biol 2020; 2089:159-166. [PMID: 31773653 DOI: 10.1007/978-1-0716-0163-1_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
The electrophoretic mobility shift assay (EMSA) is commonly used for the study of nucleic acid-binding proteins. The technique can be used to demonstrate that a protein is binding to RNA or DNA through visualization of a shift in electrophoretic mobility of the nucleic acid band. A major disadvantage of the EMSA is that it does not always provide an absolute certitude that the band shift is due to the protein under scrutiny, as contaminants in the sample could also cause the band shift. Here we describe a variation of the standard EMSA allowing to visualize with added certitude, the co-localized band shifts of a GFP-tagged protein binding to its cognate nucleic acid target sequence stained with an intercalator, such as GelRed. Herein, we present an illustrative protocol of this useful technique called GFP-EMSA along with specific notes on its advantages and limitations.
Collapse
|
14
|
Sorenson AE, Schaeffer PM. High-Throughput Differential Scanning Fluorimetry of GFP-Tagged Proteins. Methods Mol Biol 2020; 2089:69-85. [PMID: 31773648 DOI: 10.1007/978-1-0716-0163-1_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Differential scanning fluorimetry is useful for a wide variety of applications including characterization of protein function, structure-activity relationships, drug screening, and optimization of buffer conditions for protein purification, enzyme activity, and crystallization. A limitation of classic differential scanning fluorimetry is its reliance on highly purified protein samples. This limitation is overcome through differential scanning fluorimetry of GFP-tagged proteins (DSF-GTP). DSF-GTP specifically measures the unfolding and aggregation of a target protein fused to GFP through its proximal perturbation effects on GFP fluorescence. As a result of this unique principle, DSF-GTP can specifically measure the thermal stability of a target protein in the presence of other proteins. Additionally, the GFP provides a unique in-assay quality control measure. Here, we describe the workflow, steps, and important considerations for executing a DSF-GTP experiment in a 96-well plate format.
Collapse
Affiliation(s)
- Alanna E Sorenson
- Molecular and Cell Biology, College of Public Health, Medical and Veterinary Sciences, James Cook University, Douglas, QLD, Australia
| | - Patrick M Schaeffer
- Molecular and Cell Biology, College of Public Health, Medical and Veterinary Sciences, James Cook University, Douglas, QLD, Australia.
| |
Collapse
|
15
|
Yum C, Ahn T, Shim WS. Development of a Novel Blue Fluorescent Gene-encoded Calcium Indicator Modified from GCaMP3. J Fluoresc 2020; 30:1287-1293. [PMID: 32833117 DOI: 10.1007/s10895-020-02606-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 08/11/2020] [Indexed: 10/23/2022]
Abstract
Intracellular calcium can be monitored by various calcium-specific fluorescent dyes including gene-encoded calcium indicators (GECI). GCaMP is a widely-used GECI that emits green fluorescence proportional to the level of intracellular calcium. However, since many tagging proteins also emit green fluorescence, GCaMP cannot be used with another green fluorescent protein. Therefore, it would be ideal to develop a GECI that has a distinct color profile other than green. In this regard, we developed a novel blue fluorescent calcium indicator modified from GCaMP called Ser222-Ala229-Cys330-BCaMP3. Specifically, a simple threonine to histidine substitution to a green fluorescent Cys330-GCaMP3 successfully changed its fluorescence to blue (Cys330-BCaMP3, B for blue). Furthermore, a couple of additional amino acid substitutions resulted in more enhanced blue fluorescence intensity. Among other Cys330-BCaMP3 variants, it was found that Ser222-Ala229-Cys330-BCaMP3 exhibited the strongest blue fluorescence intensity. When Ser222-Ala229-Cys330-BCaMP3 was co-expressed with TRPA1 - a non-selective cation channel - in HEK293T cells, it showed moderate blue fluorescence. One of the drawbacks of Ser222-Ala229-Cys330-BCaMP3 was that the fluorescence intensity was not enough when cells were cultured under 37°C. However, this limitation was circumvented by lowering cell culture temperature to 28°C, allowing much more enhanced blue fluorescence. Although Ser222-Ala229-Cys330-BCaMP3 mandates further optimization, the present study has found a promising blue fluorescent GECI that is derived from GCaMP3.
Collapse
Affiliation(s)
- Chorok Yum
- College of Pharmacy, Gachon University, Hambakmoeiro 191, Yeonsu-gu, Incheon, 21936, Republic of Korea
| | - Taekyoung Ahn
- College of Pharmacy, Gachon University, Hambakmoeiro 191, Yeonsu-gu, Incheon, 21936, Republic of Korea
| | - Won-Sik Shim
- College of Pharmacy, Gachon University, Hambakmoeiro 191, Yeonsu-gu, Incheon, 21936, Republic of Korea. .,Gachon Institute of Pharmaceutical Sciences, Hambakmoeiro 191, Yeonsu-gu, Incheon, 21936, Republic of Korea. .,College of Pharmacy, Gachon University, Incheon, 406-799, South Korea.
| |
Collapse
|
16
|
Nagibina GS, Melnik TN, Glukhova KA, Uversky VN, Melnik BS. Intrinsic disorder-based design of stable globular proteins. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 174:157-186. [PMID: 32828465 DOI: 10.1016/bs.pmbts.2020.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Directed stabilization of globular proteins via substitution of a minimal number of amino acid residues is one of the most complicated experimental tasks. In this work, we have successfully used algorithms for the evaluation of intrinsic disorder predisposition (such as PONDR® FIT and IsUnstruct) as tools for searching for the weakened regions in structured globular proteins. We have shown that the weakened regions found by these programs as regions with highest levels of predicted intrinsic disorder predisposition are a suitable target for introduction of stabilizing mutations.
Collapse
Affiliation(s)
- Galina S Nagibina
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Tatiana N Melnik
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Ksenia A Glukhova
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States; Laboratory of New Methods in Biology, Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow Region, Russia.
| | - Bogdan S Melnik
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
| |
Collapse
|
17
|
Gao J, Qian H, Guo X, Mi Y, Guo J, Zhao J, Xu C, Zheng T, Duan M, Tang Z, Lin C, Shen Z, Jiang Y, Wang X. The signal peptide of Cry1Ia can improve the expression of eGFP or mCherry in Escherichia coli and Bacillus thuringiensis and enhance the host's fluorescent intensity. Microb Cell Fact 2020; 19:112. [PMID: 32448275 PMCID: PMC7247199 DOI: 10.1186/s12934-020-01371-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 05/16/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The signal peptides (SPs) of secretory proteins are frequently used or modified to guide recombinant proteins outside the cytoplasm of prokaryotic cells. In the periplasmic space and extracellular environment, recombinant proteins are kept away from the intracellular proteases and often they can fold correctly and efficiently. Consequently, expression levels of the recombinant protein can be enhanced by the presence of a SP. However, little attention has been paid to the use of SPs with low translocation efficiency for recombinant protein production. In this paper, the function of the signal peptide of Bacillus thuringiensis (Bt) Cry1Ia toxin (Iasp), which is speculated to be a weak translocation signal, on regulation of protein expression was investigated using fluorescent proteins as reporters. RESULTS When fused to the N-terminal of eGFP or mCherry, the Iasp can improve the expression of the fluorescent proteins and as a consequence enhance the fluorescent intensity of both Escherichia coli and Bt host cells. Real-time quantitative PCR analysis revealed the higher transcript levels of Iegfp over those of egfp gene in E. coli TG1 cells. By immunoblot analysis and confocal microscope observation, lower translocation efficiency of IeGFP was demonstrated. The novel fluorescent fusion protein IeGFP was then used to compare the relative strengths of cry1Ia (Pi) and cry1Ac (Pac) gene promoters in Bt strain, the latter promoter proving the stronger. The eGFP reporter, by contrast, cannot indicate unambiguously the regulation pattern of Pi at the same level of sensitivity. The fluorescent signals of E. coli and Bt cells expressing the Iasp fused mCherry (ImCherry) were also enhanced. Importantly, the Iasp can also enhanced the expression of two difficult-to-express proteins, matrix metalloprotease-13 (MMP13) and myostatin (growth differentiating factor-8, GDF8) in E. coli BL21-star (DE3) strain. CONCLUSIONS We identified the positive effects of a weak signal peptide, Iasp, on the expression of fluorescent proteins and other recombinant proteins in bacteria. The produced IeGFP and ImCherry can be used as novel fluorescent protein variants in prokaryotic cells. The results suggested the potential application of Iasp as a novel fusion tag for improving the recombinant protein expression.
Collapse
Affiliation(s)
- Jianhua Gao
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China.
| | - Hongmei Qian
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Xiaoqin Guo
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Yi Mi
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Junpei Guo
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Juanli Zhao
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Chao Xu
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Ting Zheng
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Ming Duan
- Experimental Teaching Center, Shanxi Agricultural University, Taigu, 030801, China
| | - Zhongwei Tang
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China
| | - Chaoyang Lin
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Zhicheng Shen
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Yiwei Jiang
- Department of Agronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - Xingchun Wang
- College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, China.
| |
Collapse
|
18
|
Gottipati K, Woodson M, Choi KH. Membrane binding and rearrangement by chikungunya virus capping enzyme nsP1. Virology 2020; 544:31-41. [PMID: 32174512 PMCID: PMC7103501 DOI: 10.1016/j.virol.2020.02.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/17/2020] [Accepted: 02/23/2020] [Indexed: 01/20/2023]
Abstract
Alphavirus genome replication is carried out by the viral replication complex inside modified membrane structures called spherules. The viral nonstructural protein 1 (nsP1) is the only membrane-associated protein that anchors the replication complex to the cellular membranes. Although an internal amphipathic helix of nsP1 is critical for membrane association, the mechanism of nsP1 interaction with membranes and subsequent membrane reorganization is not well understood. We studied the membrane interaction of chikungunya virus (CHIKV) nsP1 and show that both the CHIKV nsP1 protein and the amphipathic peptide specifically bind to negatively charged phospholipid vesicles. Using cryo-electron microscopy, we further show that nsP1 forms a contiguous coat on lipid vesicles and induces structural reorganization, while the amphipathic peptide alone failed to deform the membrane bilayer. This suggests that although amphipathic helix of nsP1 is required for initial membrane binding, the remaining cytoplasmic domain of nsP1 is involved in the subsequent membrane reorganization.
Collapse
Affiliation(s)
- Keerthi Gottipati
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, USA.
| | - Michael Woodson
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, USA
| | - Kyung H Choi
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, USA.
| |
Collapse
|
19
|
Nagibina GS, Glukhova KA, Uversky VN, Melnik TN, Melnik BS. Intrinsic Disorder-Based Design of Stable Globular Proteins. Biomolecules 2019; 10:E64. [PMID: 31906016 PMCID: PMC7022990 DOI: 10.3390/biom10010064] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/18/2019] [Accepted: 12/20/2019] [Indexed: 11/24/2022] Open
Abstract
Directed stabilization of globular proteins via substitution of a minimal number of amino acid residues is one of the most complicated experimental tasks. This work summarizes our research on the effect of amino acid substitutions on the protein stability utilizing the outputs of the analysis of intrinsic disorder predisposition of target proteins. This allowed us to formulate the basis of one of the possible approaches to the stabilization of globular proteins. The idea is quite simple. To stabilize a protein as a whole, one needs to find its "weakest spot" and stabilize it, but the question is how this weak spot can be found in a query protein. Our approach is based on the utilization of the computational tools for the per-residue evaluation of intrinsic disorder predisposition to search for the "weakest spot" of a query protein (i.e., the region(s) with the highest local predisposition for intrinsic disorder). When such "weakest spot" is found, it can be stabilized through a limited number of point mutations by introducing order-promoting residues at hot spots, thereby increasing structural stability of a protein as a whole. Using this approach, we were able to obtain stable mutant forms of several globular proteins, such as Gαo, GFP, ribosome protein L1, and circular permutant of apical domain of GroEL.
Collapse
Affiliation(s)
- Galina S. Nagibina
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia; (G.S.N.); (K.A.G.); (T.N.M.)
| | - Ksenia A. Glukhova
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia; (G.S.N.); (K.A.G.); (T.N.M.)
| | - Vladimir N. Uversky
- Department of Molecular Medicine and Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33620, USA;
- Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 142290 Pushchino, Moscow Region, Russia
| | - Tatiana N. Melnik
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia; (G.S.N.); (K.A.G.); (T.N.M.)
| | - Bogdan S. Melnik
- Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia; (G.S.N.); (K.A.G.); (T.N.M.)
| |
Collapse
|
20
|
Tai Y, Takaba K, Hanazono Y, Dao HA, Miki K, Takeda K. X-ray crystallographic studies on the hydrogen isotope effects of green fluorescent protein at sub-ångström resolutions. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2019; 75:1096-1106. [PMID: 31793903 DOI: 10.1107/s2059798319014608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 10/28/2019] [Indexed: 11/10/2022]
Abstract
Hydrogen atoms are critical to the nature and properties of proteins, and thus deuteration has the potential to influence protein function. In fact, it has been reported that some deuterated proteins show different physical and chemical properties to their protiated counterparts. Consequently, it is important to investigate protonation states around the active site when using deuterated proteins. Here, hydrogen isotope effects on the S65T/F99S/M153T/V163A variant of green fluorescent protein (GFP), in which the deprotonated B form is dominant at pH 8.5, were investigated. The pH/pD dependence of the absorption and fluorescence spectra indicates that the protonation state of the chromophore is the same in protiated GFP in H2O and protiated GFP in D2O at pH/pD 8.5, while the pKa of the chromophore became higher in D2O. Indeed, X-ray crystallographic analyses at sub-ångström resolution revealed no apparent changes in the protonation state of the chromophore between the two samples. However, detailed comparisons of the hydrogen OMIT maps revealed that the protonation state of His148 in the vicinity of the chromophore differed between the two samples. This indicates that protonation states around the active site should be carefully adjusted to be the same as those of the protiated protein when neutron crystallographic analyses of proteins are performed.
Collapse
Affiliation(s)
- Yang Tai
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kiyofumi Takaba
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yuya Hanazono
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Hoang Anh Dao
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kunio Miki
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kazuki Takeda
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| |
Collapse
|
21
|
Abdallah W, Chirino V, Wheeldon I, Banta S. Catalysis of Thermostable Alcohol Dehydrogenase Improved by Engineering the Microenvironment through Fusion with Supercharged Proteins. Chembiochem 2019; 20:1827-1837. [PMID: 30859665 DOI: 10.1002/cbic.201900066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/09/2019] [Indexed: 11/09/2022]
Abstract
The enzymatic microenvironment can impact biocatalytic activity; however, these effects can be difficult to investigate as mutations and fusions can introduce multiple variables and overlapping effects. The fusion of a supercharged protein is a potentially facile means to alter the enzymatic microenvironment. We have investigated complexes made between a thermostable alcohol dehydrogenase (AdhD) and superfolding green fluorescent protein (sfGFP) mutants with extreme surface charges. Three charged sfGFP variants, -30, 0, and +36 were covalently attached to AdhD through the SpyCatcher/SpyTag system. Specific rates for the NAD+ -dependent oxidation of butane-2,3-diol were significantly increased in the -30 sfGFP complex, a mixed effect was seen for the 0 sfGFP complexes, and the rates were unaffected by +36 sfGFP complexation. Reactions performed at various pH values (7.8-9.8) and salt concentrations (7.75-500 mm) showed that there was a complex interplay between these effects that was consistent with fusion proteins affecting the local ionic strength, as opposed to the local pH. Steady-state kinetic analyses were performed with the -30 and 0 AdhD-sfGFP complexes. The overall catalytic efficiency was dependent on the charge of the fused sfGFP variant; the -30 sfGFP fusions exhibited the largest beneficial effects at pH 8.8. The impact of the fusions on the apparent ionic strength provides further insight into the effects of charged patches observed on metabolon-forming enzyme complexes.
Collapse
Affiliation(s)
- Walaa Abdallah
- Department of Chemical Engineering, Columbia University, 500 West 120th Street, Room 801, New York, NY, 10027, USA
| | - Vanessa Chirino
- Department of Biochemistry, Barnard College, 3009 Broadway, New York, NY, 10027, USA
| | - Ian Wheeldon
- Department of Chemical and Environmental Engineering, University of California, Riverside, 900 University Avenue, Riverside, CA, 92521, USA
| | - Scott Banta
- Department of Chemical Engineering, Columbia University, 500 West 120th Street, Room 801, New York, NY, 10027, USA
| |
Collapse
|
22
|
|
23
|
Meiresonne NY, Consoli E, Mertens LM, Chertkova AO, Goedhart J, den Blaauwen T. Superfolder mTurquoise2 ox optimized for the bacterial periplasm allows high efficiency in vivo FRET of cell division antibiotic targets. Mol Microbiol 2019; 111:1025-1038. [PMID: 30648295 PMCID: PMC6850650 DOI: 10.1111/mmi.14206] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2019] [Indexed: 11/30/2022]
Abstract
Fluorescent proteins (FPs) are of vital importance to biomedical research. Many of the currently available fluorescent proteins do not fluoresce when expressed in non-native environments, such as the bacterial periplasm. This strongly limits the options for applications that employ multiple FPs, such as multiplex imaging and Förster resonance energy transfer (FRET). To address this issue, we have engineered a new cyan fluorescent protein based on mTurquoise2 (mTq2). The new variant is dubbed superfolder turquoise2ox (sfTq2ox ) and is able to withstand challenging, oxidizing environments. sfTq2ox has improved folding capabilities and can be expressed in the periplasm at higher concentrations without toxicity. This was tied to the replacement of native cysteines that may otherwise form promiscuous disulfide bonds. The improved sfTq2ox has the same spectroscopic properties as mTq2, that is, high fluorescence lifetime and quantum yield. The sfTq2ox -mNeongreen FRET pair allows the detection of periplasmic protein-protein interactions with energy transfer rates exceeding 40%. Employing the new FRET pair, we show the direct interaction of two essential periplasmic cell division proteins FtsL and FtsB and disrupt it by mutations, paving the way for in vivo antibiotic screening. SIGNIFICANCE: The periplasmic space of Gram-negative bacteria contains many regulatory, transport and cell wall-maintaining proteins. A preferred method to investigate these proteins in vivo is by the detection of fluorescent protein fusions. This is challenging since most fluorescent proteins do not fluoresce in the oxidative environment of the periplasm. We assayed popular fluorescent proteins for periplasmic functionality and describe key factors responsible for periplasmic fluorescence. Using this knowledge, we engineered superfolder mTurquoise2ox (sfTq2ox ), a new cyan fluorescent protein, capable of bright fluorescence in the periplasm. We show that our improvements come without a trade-off from its parent mTurquoise2. Employing sfTq2ox as FRET donor, we show the direct in vivo interaction and disruption of unique periplasmic antibiotic targets FtsB and FtsL.
Collapse
Affiliation(s)
- Nils Y. Meiresonne
- Bacterial Cell Biology & Physiology, Swammerdam Institute for Life SciencesUniversity of AmsterdamScience Park 904Amsterdam1098 XHThe Netherlands
| | - Elisa Consoli
- Bacterial Cell Biology & Physiology, Swammerdam Institute for Life SciencesUniversity of AmsterdamScience Park 904Amsterdam1098 XHThe Netherlands
| | - Laureen M.Y. Mertens
- Bacterial Cell Biology & Physiology, Swammerdam Institute for Life SciencesUniversity of AmsterdamScience Park 904Amsterdam1098 XHThe Netherlands
| | - Anna O. Chertkova
- Molecular Cytology and van Leeuwenhoek Centre for Advanced MicroscopySwammerdam Institute for Life Sciences, University of AmsterdamScience Park 904Amsterdam1098 XHThe Netherlands
| | - Joachim Goedhart
- Molecular Cytology and van Leeuwenhoek Centre for Advanced MicroscopySwammerdam Institute for Life Sciences, University of AmsterdamScience Park 904Amsterdam1098 XHThe Netherlands
| | - Tanneke den Blaauwen
- Bacterial Cell Biology & Physiology, Swammerdam Institute for Life SciencesUniversity of AmsterdamScience Park 904Amsterdam1098 XHThe Netherlands
| |
Collapse
|
24
|
Zhong S, Rivera-Molina F, Rivetta A, Toomre D, Santos-Sacchi J, Navaratnam D. Seeing the long tail: A novel green fluorescent protein, SiriusGFP, for ultra long timelapse imaging. J Neurosci Methods 2018; 313:68-76. [PMID: 30578868 PMCID: PMC9431725 DOI: 10.1016/j.jneumeth.2018.12.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/11/2018] [Accepted: 12/11/2018] [Indexed: 11/17/2022]
Abstract
BACKGROUND Fluorescent proteins (FPs) have widespread uses in cell biology. However, the practical applications of FPs are significantly limited due to their rapid photobleaching and misfolding when fused to target proteins. NEW METHOD Using a combination of novel and known mutations to eGFP, we developed a well folded and very photostable variant, SiriusGFP. RESULTS The fluorescence spectrum indicated that the excitation and emission peaks of SiriusGFP were red-shifted by 16 and 8 nm, respectively. Co- operative effects of two key mutations, S147R and S205 V, contribute to its photostability. SiriusGFP tagged to the mitochondrial outer membrane protein Omp25 showed sustained fluorescence during continuous 3D-scanning confocal imaging (4D confocal) compared to eGFP-tagged Omp25. Furthermore, with super-resolution structured illumination microscopy (SIM) we demonstrate marked improvements in image quality and resolution (130 nm in XY axis, and 310 nm in Z axis), as well as, decreased artifacts due to photobleaching. COMPARISON WITH EXISTING METHOD(S) Compared to eGFP. SiriusGFP shows a 2-fold increase in photostability in vitro, and folds well when fused to the N- and C- termini of cytoplasmic and membrane proteins. While its quantum yield is ˜3 fold lower than eGFP, its decreased brightness was more than compensated by its increasedphotostability in different experimental paradigms allowing practical experimentation without dynamic adjustment of light intensity or fluorescence sampling times. CONCLUSIONS We have developed a variant of eGFP, SiriusGFP, that shows over a two fold increase in photostability with utility in methods requiring sustained or high intensity excitation as in 4D confocal or SIM imaging.
Collapse
Affiliation(s)
- Sheng Zhong
- Dept. of Surgery (Otolaryngology), Yale University School of Medicine, New Haven, CT, 06511, United States; Dept. of Neurology, United States
| | | | | | | | - Joseph Santos-Sacchi
- Dept. of Surgery (Otolaryngology), Yale University School of Medicine, New Haven, CT, 06511, United States; Dept. of Neuroscience, United States; Dept. of Cellular and Molecular Physiology, United States
| | - Dhasakumar Navaratnam
- Dept. of Surgery (Otolaryngology), Yale University School of Medicine, New Haven, CT, 06511, United States; Dept. of Neuroscience, United States; Dept. of Neurology, United States.
| |
Collapse
|
25
|
Ghosh S, Wang X, Wang J, Nguyen PD, Janczak CM, Aspinwall CA. Enhanced Fluorescent Protein Activity in Polymer Scaffold-Stabilized Phospholipid Nanoshells Using Neutral Redox Initiator Polymerization Conditions. ACS OMEGA 2018; 3:15890-15899. [PMID: 30533583 PMCID: PMC6276202 DOI: 10.1021/acsomega.8b01661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 11/09/2018] [Indexed: 06/09/2023]
Abstract
Phospholipid nanoshells, for example, liposomes, provide a versatile enabling platform for the development of nanometer-sized biosensors and molecular delivery systems. Utilization of phospholipid nanoshells is limited by the inherent instability in complex biological environments, where the phospholipid nanoshell may disassemble and degrade, thus releasing the contents and destroying sensor function. Polymer scaffold stabilization (PSS), wherein the phospholipid nanoshells are prepared by partitioning reactive monomers into the lipid bilayer lamella followed by radical polymerization, has emerged to increase phospholipid nanoshell stability. In this work, we investigated the effects of three different radical initiator conditions to fabricate stable PSS-phospholipid nanoshells yet retain the activity of encapsulated model fluorescent sensor proteins. To identify nondestructive initiation conditions, UV photoinitiation, neutral redox initiation, and thermal initiation were investigated as a function of PSS-phospholipid nanoshell stabilization and fluorescence emission intensity of enhanced green fluorescent protein (eGFP) and tandem dimer Tomato (td-Tomato). All three initiator approaches yielded comparably stable PSS-phospholipid nanoshells, although slight variations in PSS-phospholipid nanoshell size were observed, ranging from ca. 140 nm for unstabilized phospholipid nanoshells to 300-500 nm for PSS-phospholipid nanoshells. Fluorescence emission intensity of encapsulated eGFP was completely attenuated under thermal initiation (0% vs control), moderately attenuated under UV photoinitiation (40 ± 4% vs control), and unaffected by neutral redox initiation (97 ± 3% vs control). Fluorescence emission intensity of encapsulated td-Tomato was significantly attenuated under thermal initiation (13 ± 3% vs control), moderately attenuated UV photoinitiation (64 ± 5% vs control), and unaffected by neutral redox initiation (98% ± 4% vs control). Therefore, the neutral redox initiation method provides a significant advancement toward the preparation of protein-functionalized PSS-phospholipid nanoshells. These results should help to guide future applications and designs of biosensor platforms using PSS-phospholipid nanoshells and other polymer systems employing protein transducers.
Collapse
Affiliation(s)
- Surajit Ghosh
- Department
of Chemistry and Biochemistry, BIO5 Institute, and Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Xuemin Wang
- Department
of Chemistry and Biochemistry, BIO5 Institute, and Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Jinyan Wang
- Department
of Chemistry and Biochemistry, BIO5 Institute, and Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Phuong-Diem Nguyen
- Department
of Chemistry and Biochemistry, BIO5 Institute, and Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Colleen M. Janczak
- Department
of Chemistry and Biochemistry, BIO5 Institute, and Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| | - Craig A. Aspinwall
- Department
of Chemistry and Biochemistry, BIO5 Institute, and Department of Biomedical Engineering, The University of Arizona, Tucson, Arizona 85721, United States
| |
Collapse
|
26
|
Jarugula S, Gowda S, Dawson WO, Naidu RA. Development of infectious cDNA clones of Grapevine leafroll-associated virus 3 and analyses of the 5' non-translated region for replication and virion formation. Virology 2018; 523:89-99. [PMID: 30103103 DOI: 10.1016/j.virol.2018.07.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/19/2018] [Accepted: 07/21/2018] [Indexed: 01/28/2023]
Abstract
Infectious cDNA clones were developed for Grapevine leafroll-associated virus 3 (GLRaV-3, genus Ampelovirus, family Closteroviridae). In vitro RNA transcripts generated from cDNA clones showed replication via the production of 3'-coterminal subgenomic (sg) mRNAs in Nicotiana benthamiana protoplasts. The detection of sgRNAs and the recovery of progeny recombinant virions from N. benthamiana leaves agroinfiltrated with full-length cDNA clones confirmed RNA replication and virion formation. The 5' non-translated region (5' NTR) of GLRaV-3 was exchangeable between genetic variants and complement the corresponding cognate RNA functions in trans. Mutational analysis of the 5' NTR in minireplicon cDNA clones showed that the conserved 40 nucleotides at the 5'-terminus were indispensable for replication, compared to downstream variable portion of the 5' NTR. Some of the functional mutations in the 5' NTR were tolerated in full-length cDNA clones and produced sgRNAs and virions in N. benthamiana leaves, whereas other mutations affected replication and virion formation.
Collapse
Affiliation(s)
- Sridhar Jarugula
- Department of Plant Pathology, Irrigated Agriculture Research and Extension Center, Washington State University, WA 99350, United States
| | - Siddarame Gowda
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - William O Dawson
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL, United States
| | - Rayapati A Naidu
- Department of Plant Pathology, Irrigated Agriculture Research and Extension Center, Washington State University, WA 99350, United States.
| |
Collapse
|
27
|
Gil-Garcia M, Bañó-Polo M, Varejão N, Jamroz M, Kuriata A, Díaz-Caballero M, Lascorz J, Morel B, Navarro S, Reverter D, Kmiecik S, Ventura S. Combining Structural Aggregation Propensity and Stability Predictions To Redesign Protein Solubility. Mol Pharm 2018; 15:3846-3859. [DOI: 10.1021/acs.molpharmaceut.8b00341] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Marcos Gil-Garcia
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain
| | - Manuel Bañó-Polo
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain
| | - Nathalia Varejão
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain
| | - Michal Jamroz
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, 00-927 Warsaw, Poland
| | - Aleksander Kuriata
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, 00-927 Warsaw, Poland
| | - Marta Díaz-Caballero
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain
| | - Jara Lascorz
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain
| | - Bertrand Morel
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
| | - Susanna Navarro
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain
| | - David Reverter
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain
| | - Sebastian Kmiecik
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, 00-927 Warsaw, Poland
| | - Salvador Ventura
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra (Barcelona) 08193, Spain
| |
Collapse
|
28
|
Claxton DP, Gouaux E. Expression and purification of a functional heteromeric GABAA receptor for structural studies. PLoS One 2018; 13:e0201210. [PMID: 30028870 PMCID: PMC6054424 DOI: 10.1371/journal.pone.0201210] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 07/10/2018] [Indexed: 01/08/2023] Open
Abstract
The GABA-gated chloride channels of the Cys-loop receptor family, known as GABAA receptors, function as the primary gatekeepers of fast inhibitory neurotransmission in the central nervous system. Formed by the pentameric arrangement of five identical or homologous subunits, GABAA receptor subtypes are defined by the subunit composition that shape ion channel properties. An understanding of the structural basis of distinct receptor properties has been hindered by the absence of high resolution structural information for heteromeric assemblies. Robust heterologous expression and purification protocols of high expressing receptor constructs are vital for structural studies. Here, we describe a unique approach to screen for well-behaving and functional GABAA receptor subunit assemblies by using the Xenopus oocyte as an expression host in combination with fluorescence detection size exclusion chromatography (FSEC). To detect receptor expression, GFP fusions were introduced into the α1 subunit isoform. In contrast to expression of α1 alone, co-expression with the β subunit promoted formation of monodisperse assemblies. Mutagenesis experiments suggest that the α and β subunits can tolerate large truncations in the non-conserved M3/M4 cytoplasmic loop without compromising oligomeric assembly or GABA-gated channel activity, although removal of N-linked glycosylation sites is negatively correlated with expression level. Additionally, we report methods to improve GABAA receptor expression in mammalian cell culture that employ recombinant baculovirus transduction. From these methods we have identified a well-behaving minimal functional construct for the α1/β1 GABAA receptor subtype that can be purified in milligram quantities while retaining high affinity agonist binding activity.
Collapse
Affiliation(s)
- Derek P. Claxton
- Vollum Institute, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Eric Gouaux
- Vollum Institute, Oregon Health and Science University, Portland, Oregon, United States of America
- Howard Hughes Medical Institute, Oregon Health and Science University, Portland, Oregon, United States of America
| |
Collapse
|
29
|
Qiao W, Falk BW. Efficient Protein Expression and Virus-Induced Gene Silencing in Plants Using a Crinivirus-Derived Vector. Viruses 2018; 10:E216. [PMID: 29695039 PMCID: PMC5977209 DOI: 10.3390/v10050216] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 04/19/2018] [Accepted: 04/21/2018] [Indexed: 01/12/2023] Open
Abstract
Plant virus-based vectors are valuable tools for recombinant gene expression and functional genomics for both basic and applied research. In this study, Lettuce infectious yellows virus (LIYV) of the genus Crinivirus was engineered into a virus vector that is applicable for efficient protein expression and virus-induced gene silencing (VIGS) in plants. We examined gene replacement and “add a gene” strategies to develop LIYV-derived vectors for transient expression of the green fluorescent protein (GFP) reporter in Nicotiana benthamiana plants. The latter yielded higher GFP expression and was further examined by testing the effects of heterologous controller elements (CEs). A series of five vector constructs with progressively extended LIYV CP sgRNA CEs were tested, the longest CE gave the highest GFP expression but lower virus accumulation. The whitefly transmissibility of the optimized vector construct to other host plants, and the capability to accommodate and express a larger gene, a 1.8 kb β-glucuronidase (GUS) gene, were confirmed. Furthermore, the LIYV vector was also validated VIGS by silencing the endogenous gene, phytoene desaturase (PDS) in N. benthamiana plants, and the transgene GFP in N. benthamiana line 16c plants. Therefore, LIYV-derived vectors could provide a technical reference for developing vectors of other economically important criniviruses.
Collapse
Affiliation(s)
- Wenjie Qiao
- Department of Plant Pathology, University of California, Davis, 95616 CA, USA.
| | - Bryce W Falk
- Department of Plant Pathology, University of California, Davis, 95616 CA, USA.
| |
Collapse
|
30
|
Borovsky D, Nauewelaers S, Powell CA, Shatters RG. Cloning, genetic engineering and characterization of TMOF expressed in Saccharomyces cerevisiae to control larval mosquitoes. JOURNAL OF INSECT PHYSIOLOGY 2018; 106:134-146. [PMID: 28109905 DOI: 10.1016/j.jinsphys.2017.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 06/06/2023]
Abstract
Trypsin modulating oostatic factor, a decapaptide isolated from the ovaries of A. aegypti, is the physiological factor that terminates the trypsin biosynthesis after the blood meal. Earlier results obtained from feeding mosquito larvae and injecting female mosquitoes with TMOF show that trypsin biosynthesis and egg development are inhibited, indicating that TMOF traverses the gut epithelial cells and modulates trypsin biosynthesis, making it a potential larvacidal peptide hormone. Therefore, TMOF and TMOF green fluorescent protein (GFP) fusion protein with a trypsin cleavage site, allowing TMOF release in the larval gut, were expressed in S. cerevisiae cells that were transformed using homologous recombination at ura3-52 with an engineered plasmid (pYDB2) carrying tmfA and gfp-tmfA and a strong galactose promoter (PGAL1). Southern blot analyses showed that each cell incorporated a single tmfA or gfp-tmfA. Western blot analyses of cells that were fermented up to 48h showed that the engineered S. cerevisiae cells synthesized both TMOF and GFP-TMOF and heat treatment did not affect the recombinant proteins. Engineered S. cerevisiae (3×108cells) that were fermented for 4h produced (2.1±0.2μg±S.E.M) of TMOF. Feeding the engineered cells producing TMOF and GFP-TMOF to larval mosquito caused high mortalities (66±12% and 83±8%, respectively). S. cerevisiae cells transfected with pYEX-BX carrying gfp-tmfA and (DPAR)4 or transformed by homologous recombination of pYDB2-gfp-tmfA carrying a heat shock promoter (PHP) were ineffective. Engineered heat treated yeast cells are consumed by mosquito larvae, and could be used to control mosquitoes.
Collapse
Affiliation(s)
- Dov Borovsky
- USDA-ARS, Horticultural Research Laboratory, Ft. Pierce, FL 34945, USA.
| | | | - Charles A Powell
- Indian River Research and Education Center University of Florida, FL 34945, USA
| | - Robert G Shatters
- USDA-ARS, Horticultural Research Laboratory, Ft. Pierce, FL 34945, USA
| |
Collapse
|
31
|
Yi Y, Frenzel E, Spoelder J, Elzenga JTM, van Elsas JD, Kuipers OP. Optimized fluorescent proteins for the rhizosphere-associated bacterium Bacillus mycoides with endophytic and biocontrol agent potential. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:57-74. [PMID: 29195004 DOI: 10.1111/1758-2229.12607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/23/2017] [Indexed: 06/07/2023]
Abstract
Tracking of fluorescent protein (FP)-labelled rhizobacteria is a key prerequisite to gain insights into plant-bacteria interaction mechanisms. However, the performance of FPs mostly has to be optimized for the bacterial host and for the environment of intended application. We report on the construction of mutational libraries of the superfolder green fluorescent protein sfGFP and the red fluorescent protein mKate2 in the bacterium B. mycoides, which next to its potential as plant-biocontrol agent occasionally enters an endophytic lifestyle. By fluorescence-activated cell sorting and comparison of signal intensities at the colony and single-cell level, the variants sfGFP(SPS6) and mKate (KPS12) with significantly increased brightness were isolated. Their high applicability for plant-bacteria interaction studies was shown by confocal laser scanning microscopy tracking of FP-tagged B. mycoides strains after inoculation to Chinese cabbage plants in a hydroponic system. During the process of colonization, strain EC18 rapidly attached to plant roots and formed a multicellular matrix, especially at the branching regions of the root hair, which probably constitute entrance sites to establish an endophytic lifestyle. The universal applicability of the novels FPs was proven by expression from a weak promoter, dual-labelling of B. mycoides, and by excellent expression and detectability in additional soil- and rhizosphere-associated Bacillus species.
Collapse
Affiliation(s)
- Yanglei Yi
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Elrike Frenzel
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Jan Spoelder
- Plant Physiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - J Theo M Elzenga
- Plant Physiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Jan Dirk van Elsas
- Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| |
Collapse
|
32
|
Quandt EM, Traverse CC, Ochman H. Local genic base composition impacts protein production and cellular fitness. PeerJ 2018; 6:e4286. [PMID: 29362699 PMCID: PMC5774297 DOI: 10.7717/peerj.4286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 01/01/2018] [Indexed: 01/25/2023] Open
Abstract
The maintenance of a G + C content that is higher than the mutational input to a genome provides support for the view that selection serves to increase G + C contents in bacteria. Recent experimental evidence from Escherichia coli demonstrated that selection for increasing G + C content operates at the level of translation, but the precise mechanism by which this occurs is unknown. To determine the substrate of selection, we asked whether selection on G + C content acts across all sites within a gene or is confined to particular genic regions or nucleotide positions. We systematically altered the G + C contents of the GFP gene and assayed its effects on the fitness of strains harboring each variant. Fitness differences were attributable to the base compositional variation in the terminal portion of the gene, suggesting a connection to the folding of a specific protein feature. Variants containing sequence features that are thought to result in rapid translation, such as low G + C content and high levels of codon adaptation, displayed highly reduced growth rates. Taken together, our results show that purifying selection acting against A and T mutations most likely results from their tendency to increase the rate of translation, which can perturb the dynamics of protein folding.
Collapse
Affiliation(s)
- Erik M Quandt
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, United States of America
| | - Charles C Traverse
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, United States of America
| | - Howard Ochman
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, United States of America
| |
Collapse
|
33
|
Frenzel E, Legebeke J, van Stralen A, van Kranenburg R, Kuipers OP. In vivo selection of sfGFP variants with improved and reliable functionality in industrially important thermophilic bacteria. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:8. [PMID: 29371884 PMCID: PMC5771013 DOI: 10.1186/s13068-017-1008-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 12/29/2017] [Indexed: 05/03/2023]
Abstract
BACKGROUND Fluorescent reporter proteins (FP) have become an indispensable tool for the optimization of microbial cell factories and in synthetic biology per se. The applicability of the currently available FPs is, however, constrained by species-dependent performance and misfolding at elevated temperatures. To obtain functional reporters for thermophilic, biotechnologically important bacteria such as Parageobacillus thermoglucosidasius, an in vivo screening approach based on a mutational library of superfolder GFP was applied. RESULTS Flow cytometry-based benchmarking of a set of GFPs, sfGFPs and species-specific codon-optimized variants revealed that none of the proteins was satisfyingly detectable in P. thermoglucosidasius at its optimal growth temperature of 60 °C. An undirected mutagenesis approach coupled to fluorescence-activated cell sorting allowed the isolation of sfGFP variants that were extremely well expressed in the chassis background at 60 °C. Notably, a few nucleotide substitutions, including silent mutations, significantly improved the functionality and brightness. The best mutant sfGFP(N39D/A179A) showed an 885-fold enhanced mean fluorescence intensity (MFI) at 60 °C and is the most reliable reporter protein with respect to cell-to-cell variation and signal intensity reported so far. The in vitro spectral and thermostability properties were unaltered as compared to the parental sfGFP protein, strongly indicating that the combination of the amino acid exchange and an altered translation or folding speed, or protection from degradation, contribute to the strongly improved in vivo performance. Furthermore, sfGFP(N39D/A179A) and the newly developed cyan and yellow derivatives were successfully used for labeling several industrially relevant thermophilic bacilli, thus proving their broad applicability. CONCLUSIONS This study illustrates the power of in vivo isolation of thermostable proteins to obtain reporters for highly efficient fluorescence labeling. Successful expression in a variety of thermophilic bacteria proved that the novel FPs are highly suitable for imaging and flow cytometry-based studies. This enables a reliable cell tracking and single-cell-based real-time monitoring of biological processes that are of industrial and biotechnological interest.
Collapse
Affiliation(s)
- Elrike Frenzel
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Jelmer Legebeke
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Atze van Stralen
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Richard van Kranenburg
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
- Corbion, Arkselsedijk 46, 4206 AC Gorinchem, The Netherlands
| | - Oscar P. Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| |
Collapse
|
34
|
Melnik TN, Nagibina GS, Surin AK, Glukhova KA, Melnik BS. Artificial Cysteine Bridges on the Surface of Green Fluorescent Protein Affect Hydration of Its Transition and Intermediate States. Mol Biol 2018. [DOI: 10.1134/s0026893318010120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
35
|
Mastop M, Bindels DS, Shaner NC, Postma M, Gadella TWJ, Goedhart J. Characterization of a spectrally diverse set of fluorescent proteins as FRET acceptors for mTurquoise2. Sci Rep 2017; 7:11999. [PMID: 28931898 PMCID: PMC5607329 DOI: 10.1038/s41598-017-12212-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 09/05/2017] [Indexed: 01/13/2023] Open
Abstract
The performance of Förster Resonance Energy Transfer (FRET) biosensors depends on brightness and photostability, which are dependent on the characteristics of the fluorescent proteins that are employed. Yellow fluorescent protein (YFP) is often used as an acceptor but YFP is prone to photobleaching and pH changes. In this study, we evaluated the properties of a diverse set of acceptor fluorescent proteins in combination with the optimized CFP variant mTurquoise2 as the donor. To determine the theoretical performance of acceptors, the Förster radius was determined. The practical performance was determined by measuring FRET efficiency and photostability of tandem fusion proteins in mammalian cells. Our results show that mNeonGreen is the most efficient acceptor for mTurquoise2 and that the photostability is better than SYFP2. The non-fluorescent YFP variant sREACh is an efficient acceptor, which is useful in lifetime-based FRET experiments. Among the orange and red fluorescent proteins, mCherry and mScarlet-I are the best performing acceptors. Several new pairs were applied in a multimolecular FRET based sensor for detecting activation of a heterotrimeric G-protein by G-protein coupled receptors. Overall, the sensor with mNeonGreen as acceptor and mTurquoise2 as donor showed the highest dynamic range in ratiometric FRET imaging experiments with the G-protein sensor.
Collapse
Affiliation(s)
- Marieke Mastop
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands
| | - Daphne S Bindels
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands
| | - Nathan C Shaner
- Department of Photobiology and Bioimaging, The Scintillon Institute, San Diego, California, United States of America
| | - Marten Postma
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands
| | - Theodorus W J Gadella
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands
| | - Joachim Goedhart
- Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE, Amsterdam, The Netherlands.
| |
Collapse
|
36
|
Metola A, Bouchet AM, Alonso-Mariño M, Diercks T, Mäler L, Goñi FM, Viguera AR. Purification and characterization of the colicin A immunity protein in detergent micelles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2181-2192. [PMID: 28803731 DOI: 10.1016/j.bbamem.2017.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 08/06/2017] [Accepted: 08/09/2017] [Indexed: 11/18/2022]
Abstract
The immunity proteins against pore-forming colicins represent a family of integral membrane proteins that reside in the inner membrane of producing cells. Cai, the colicin A immunity protein, was characterized here in detergent micelles by circular dichroism (CD), size exclusion chromatography, chemical cross-linking, nuclear magnetic resonance (NMR) spectroscopy, cysteine accessibility, and colicin A binding in detergent micelles. Bile-salt derivatives induced extensive protein polymerization that precluded further investigation. The physical characterization of detergent-solubilized protein indicates that phosphate-containing detergents are more efficient in extracting, solubilizing and maintaining Cai in a monomeric state. Yet, their capacity to ensure protein activity, reconstitution, helix packing, and high-quality NMR spectra was inferior to that of milder detergents. Solvent ionic strength and composition greatly modified the solubilizing capacity of milder detergents. Most importantly, binding to the colicin A pore-forming domain (pf-ColA) occurred almost exclusively in sugar-derived detergents. The relative performance of the different detergents in each experiment depends on their impact not only on Cai structure, solubility and oligomerization state, but also on other reaction components and technical aspects. Thus, proteoliposomes were best obtained from protein in LDAO micelles, possibly also due to indirect effects on the lipidic bilayer. The compatibility of a detergent with Cai/pf-ColA complex formation is influenced by its effect on the conformational landscape of each protein, where detergent-mediated pf-ColA denaturation could also lead to negative results. The NMR spectra were greatly affected by the solubility, monodispersity, fold and dynamics of the protein-detergent complexes, and none of those tested here provided NMR spectra of sufficient quality to allow for peak assignment. Cai function could be proven in alkyl glycosides and not in those detergents that afforded the best solubility, reconstitution efficiency or spectral quality indicating that these criteria cannot be taken as unambiguous proof of nativeness without the support of direct activity measurements.
Collapse
Affiliation(s)
- Ane Metola
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain
| | - Ana M Bouchet
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain
| | - Marian Alonso-Mariño
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain
| | - Tammo Diercks
- Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia Ed. 800, 48160 Derio, Spain
| | - Lena Mäler
- Department of Biochemistry and Biophysics, Center for Biomembrane Research, The Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
| | - Félix M Goñi
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain; Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa. Spain
| | - Ana R Viguera
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, 48940 Leioa, Bizkaia, Spain.
| |
Collapse
|
37
|
The development of fluorescent protein tracing vectors for multicolor imaging of clinically isolated Staphylococcus aureus. Sci Rep 2017; 7:2865. [PMID: 28588310 PMCID: PMC5460165 DOI: 10.1038/s41598-017-02930-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 04/20/2017] [Indexed: 11/08/2022] Open
Abstract
Recent advances in fluorescent protein technology provide a wide variety of biological imaging applications; however current tools for bio-imaging in the Gram-positive bacterium Staphylococcus aureus has necessitated further developments for fluorescence intensity and for a multicolor palette of fluorescent proteins. To enhance the expression of multicolor fluorescent proteins in clinical S. aureus strains, we developed new fluorescent protein expression vectors, containing the blaZ/sodp promoter consisting of the β-lactamase gene (blaZ) promoter and the ribosome binding site (RBS) of superoxide dismutase gene (sod). We found S. aureus-adapted GFP (GFPsa) driven by the blaZ/sodp promoter was highly expressed in the S. aureus laboratory strain RN4220, but not in the clinical strains, MW2 and N315, harboring the endogenous blaI gene, a repressor of the blaZ gene promoter. We therefore constructed a constitutively induced blaZ/sodp promoter (blaZ/sodp(Con)) by introducing substitution mutations into the BlaI binding motif, and this modification allowed enhanced expression of the multicolor GFP variants (GFPsa, EGFP, mEmerald, Citrine, Cerulean, and BFP) as well as codon-optimized reef coral fluorescent proteins (mCherry and AmCyan) in the S. aureus clinical strains. These new fluorescent probes provide new tools to enhance expression of multicolor fluorescent proteins and facilitate clear visualization of clinical S. aureus strains.
Collapse
|
38
|
Banerjee S, Schenkelberg CD, Jordan TB, Reimertz JM, Crone EE, Crone DE, Bystroff C. Mispacking and the Fitness Landscape of the Green Fluorescent Protein Chromophore Milieu. Biochemistry 2017; 56:736-747. [PMID: 28074648 PMCID: PMC6193456 DOI: 10.1021/acs.biochem.6b00800] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The autocatalytic maturation of the chromophore in green fluorescent protein (GFP) was thought to require the precise positioning of the side chains surrounding it in the core of the protein, many of which are strongly conserved among homologous fluorescent proteins. In this study, we screened for green fluorescence in an exhaustive set of point mutations of seven residues that make up the chromophore microenvironment, excluding R96 and E222 because mutations at these positions have been previously characterized. Contrary to expectations, nearly all amino acids were tolerated at all seven positions. Only four point mutations knocked out fluorescence entirely. However, chromophore maturation was found to be slower and/or fluorescence reduced in several cases. Selected combinations of mutations showed nonadditive effects, including cooperativity and rescue. The results provide guidelines for the computational engineering of GFPs.
Collapse
Affiliation(s)
- Shounak Banerjee
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Christian D. Schenkelberg
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Thomas B. Jordan
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Julia M. Reimertz
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Emily E. Crone
- Department of Biology, Colgate University, Hamilton, New York 13346, United States
| | - Donna E. Crone
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Christopher Bystroff
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- Department of Computer Science, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| |
Collapse
|
39
|
Stepanenko OV, Stepanenko OV, Kuznetsova IM, Uversky VN, Turoverov KK. Peculiarities of the Super-Folder GFP Folding in a Crowded Milieu. Int J Mol Sci 2016; 17:ijms17111805. [PMID: 27801849 PMCID: PMC5133806 DOI: 10.3390/ijms17111805] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/11/2016] [Accepted: 10/20/2016] [Indexed: 01/19/2023] Open
Abstract
The natural cellular milieu is crowded by large quantities of various biological macromolecules. This complex environment is characterized by a limited amount of unoccupied space, limited amounts of free water, and changed solvent properties. Obviously, such a tightly packed cellular environment is poorly mimicked by traditional physiological conditions, where low concentrations of a protein of interest are analyzed in slightly salted aqueous solutions. An alternative is given by the use of a model crowded milieu, where a protein of interest is immersed in a solution containing high concentrations of various polymers that serve as model crowding agents. An expected outcome of the presence of such macromolecular crowding agents is their ability to increase conformational stability of a globular protein due to the excluded volume effects. In line with this hypothesis, the behavior of a query protein should be affected by the hydrodynamic size and concentration of an inert crowder (i.e., an agent that does not interact with the protein), whereas the chemical nature of a macromolecular crowder should not play a role in its ability to modulate conformational properties. In this study, the effects of different crowding agents (polyethylene glycols (PEGs) of various molecular masses (PEG-600, PEG-8000, and PEG-12000), Dextran-70, and Ficoll-70) on the spectral properties and unfolding–refolding processes of the super-folder green fluorescent protein (sfGFP) were investigated. sfGFP is differently affected by different crowders, suggesting that, in addition to the expected excluded volume effects, there are some changes in the solvent properties.
Collapse
Affiliation(s)
- Olesya V Stepanenko
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., St. Petersburg 194064, Russia.
| | - Olga V Stepanenko
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., St. Petersburg 194064, Russia.
| | - Irina M Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., St. Petersburg 194064, Russia.
| | - Vladimir N Uversky
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., St. Petersburg 194064, Russia.
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd. MDC07, Tampa, FL 33612, USA.
| | - Konstantin K Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky Ave., St. Petersburg 194064, Russia.
- Institute of Physics, Nanotechnology and Telecommunications, Peter the Great St. Petersburg State Polytechnic University, 29 Polytechnicheskaya st., St. Petersburg 195251, Russia.
| |
Collapse
|
40
|
Tatineni S, Wosula EN, Bartels M, Hein GL, Graybosch RA. Temperature-Dependent Wsm1 and Wsm2 Gene-Specific Blockage of Viral Long-Distance Transport Provides Resistance to Wheat streak mosaic virus and Triticum mosaic virus in Wheat. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:724-738. [PMID: 27551888 DOI: 10.1094/mpmi-06-16-0110-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are economically important viral pathogens of wheat. Wheat cvs. Mace, carrying the Wsm1 gene, is resistant to WSMV and TriMV, and Snowmass, with Wsm2, is resistant to WSMV. Viral resistance in both cultivars is temperature sensitive and is effective at 18°C or below but not at higher temperatures. The underlying mechanisms of viral resistance of Wsm1 and Wsm2, nonallelic single dominant genes, are not known. In this study, we found that fluorescent protein-tagged WSMV and TriMV elicited foci that were approximately similar in number and size at 18 and 24°C, on inoculated leaves of resistant and susceptible wheat cultivars. These data suggest that resistant wheat cultivars at 18°C facilitated efficient cell-to-cell movement. Additionally, WSMV and TriMV efficiently replicated in inoculated leaves of resistant wheat cultivars at 18°C but failed to establish systemic infection, suggesting that Wsm1- and Wsm2-mediated resistance debilitated viral long-distance transport. Furthermore, we found that neither virus was able to enter the leaf sheaths of inoculated leaves or crowns of resistant wheat cultivars at 18°C but both were able to do so at 24°C. Thus, wheat cvs. Mace and Snowmass provide resistance at the long-distance movement stage by specifically blocking virus entry into the vasculature. Taken together, these data suggest that both Wsm1 and Wsm2 genes similarly confer virus resistance by temperature-dependent impairment of viral long-distance movement.
Collapse
Affiliation(s)
- Satyanarayana Tatineni
- 1 United States Department of Agriculture-Agricultural Research Service (USDA-ARS) and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583, U.S.A
| | | | - Melissa Bartels
- 1 United States Department of Agriculture-Agricultural Research Service (USDA-ARS) and Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583, U.S.A
| | - Gary L Hein
- 2 Department of Entomology, University of Nebraska-Lincoln; and
| | - Robert A Graybosch
- 3 USDA-ARS and Department of Agronomy and Horticulture, University of Nebraska-Lincoln
| |
Collapse
|
41
|
Glukhova KF, Marchenkov VV, Melnik TN, Melnik BS. Isoforms of green fluorescent protein differ from each other in solvent molecules 'trapped' inside this protein. J Biomol Struct Dyn 2016; 35:1215-1225. [PMID: 27045905 DOI: 10.1080/07391102.2016.1174737] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Green fluorescent protein (GFP) has been studied quite thoroughly, however, up to now some experimental data have not been explained explicitly. For example, under native conditions this protein can have two isoforms differing in their mobility in gel. In this case, no differences between the isoforms are revealed under denaturing conditions. In order to understand the difference in the isoforms of this protein, we have investigated GFP-cycle3 using mass spectrometry, gel electrophoresis, size exclusion chromatography, microcalorimetry, and spectroscopy methods under varying conditions. We have also designed and studied three mutant forms of this protein with substitutions of amino acid residues inside the GFP barrel. The mutations have allowed us to influence the formation of different GFP isoforms. Each of the mutant proteins has predominantly only one isoform. As a result of the performed research, it can be concluded that most likely the GFP isoforms differ in the solvent molecules 'trapped' inside the GFP barrel. In their turn, these molecules have an effect on the protein charge and consequently on its mobility at electrophoresis under native conditions.
Collapse
Affiliation(s)
- Kseniya F Glukhova
- a Institute of Protein Research , Russian Academy of Sciences , 142290 Pushchino , Moscow Region , Russia
| | - Victor V Marchenkov
- a Institute of Protein Research , Russian Academy of Sciences , 142290 Pushchino , Moscow Region , Russia
| | - Tatiana N Melnik
- a Institute of Protein Research , Russian Academy of Sciences , 142290 Pushchino , Moscow Region , Russia
| | - Bogdan S Melnik
- a Institute of Protein Research , Russian Academy of Sciences , 142290 Pushchino , Moscow Region , Russia
| |
Collapse
|
42
|
Liu SS, Wei X, Dong X, Xu L, Liu J, Jiang B. Structural plasticity of green fluorescent protein to amino acid deletions and fluorescence rescue by folding-enhancing mutations. BMC BIOCHEMISTRY 2015. [PMID: 26206151 PMCID: PMC4513630 DOI: 10.1186/s12858-015-0046-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Green fluorescent protein (GFP) and its derivative fluorescent proteins (FPs) are among the most commonly used reporter systems for studying gene expression and protein interaction in biomedical research. Most commercially available FPs have been optimized for their oligomerization state to prevent potential structural constraints that may interfere with the native function of fused proteins. Other approach to reducing structural constraints may include minimizing the structure of GFPs. Previous studies in an enhanced GFP variant (EGFP) identified a series of deletions that can retain GFP fluorescence. In this study, we interrogated the structural plasticity of a UV-optimized GFP variant (GFP(UV)) to amino acid deletions, characterized the effects of deletions and explored the feasibility of rescuing the fluorescence of deletion mutants using folding-enhancing mutations. METHODS Transposon mutagenesis was used to screen amino acid deletions in GFP that led to fluorescent and nonfluorescent phenotypes. The fluorescent GFP mutants were characterized for their whole-cell fluorescence and fraction soluble. Fluorescent GFP mutants with internal deletions were purified and characterized for their spectral and folding properties. Folding-ehancing mutations were introduced to deletion mutants to rescue their compromised fluorescence. RESULTS We identified twelve amino acid deletions that can retain the fluorescence of GFP(UV). Seven of these deletions are either at the N- or C- terminus, while the other five are located at internal helices or strands. Further analysis suggested that the five internal deletions diminished the efficiency of protein folding and chromophore maturation. Protein expression under hypothermic condition or incorporation of folding-enhancing mutations could rescue the compromised fluorescence of deletion mutants. In addition, we generated dual deletion mutants that can retain GFP fluorescence. CONCLUSION Our results suggested that a "size-minimized" GFP may be developed by iterative incorporation of amino acid deletions, followed by fluorescence rescue with folding-enhancing mutations.
Collapse
Affiliation(s)
- Shu-su Liu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.
| | - Xuan Wei
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.
| | - Xue Dong
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.
| | - Liang Xu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.
| | - Jia Liu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China. .,Department of Chemistry and Biochemistry, University of Maryland, College Park, USA.
| | - Biao Jiang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.
| |
Collapse
|
43
|
Abstract
Superfolder variant of the green fluorescent protein (sfGFP) became a favorite probe for examination of the unfolding–refolding processes of fluorescent proteins with beta-barrel structure owing to its reversible unfolding in comparison with other fluorescent proteins. Its benefit is the proper folding even in fusion constructions with poorly folded polypeptides. We noticed that guanidine thiocyanate affects not only the structure of protein but its chromophore directly. Therefore we studied the influence of ionic denaturants and salts including guanidine thiocyanate, guanidine hydrochloride, sodium chloride and sodium thiocyanate on spectral features of sfGFP. It was shown that moderate amounts of the studied agents do not disrupt sfGFP structure but provoke pronounced alteration of its spectral characteristics. Changes in absorption and CD spectra in visible spectral range indicate the specific binding of SCN− and Cl− anions in the sfGFP chromophore vicinity. The anion binding results in the redistribution of sfGFP molecules with neutral and anionic chromophores. This also hinders the proton transfer in the chromophore excited state, considerably decreasing the fluorescence intensity of sfGFP. Our results indicate that when ionic denaturants are used in the studies of fluorescent protein folding their effect on fluorophore charge state should be taken into account.
Collapse
|
44
|
Fernandes CS, Pina AS, Dias AM, Branco RJ, Roque ACA. A theoretical and experimental approach toward the development of affinity adsorbents for GFP and GFP-fusion proteins purification. J Biotechnol 2014; 186:13-20. [DOI: 10.1016/j.jbiotec.2014.06.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/12/2014] [Accepted: 06/16/2014] [Indexed: 11/27/2022]
|
45
|
Nantasenamat C, Simeon S, Owasirikul W, Songtawee N, Lapins M, Prachayasittikul V, Wikberg JES. Illuminating the origins of spectral properties of green fluorescent proteins via proteochemometric and molecular modeling. J Comput Chem 2014; 35:1951-66. [DOI: 10.1002/jcc.23708] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 04/28/2014] [Accepted: 07/28/2014] [Indexed: 01/06/2023]
Affiliation(s)
- Chanin Nantasenamat
- Center of Data Mining and Biomedical Informatics; Faculty of Medical Technology, Mahidol University; Bangkok 10700 Thailand
- Department of Clinical Microbiology and Applied Technology; Faculty of Medical Technology, Mahidol University; Bangkok 10700 Thailand
| | - Saw Simeon
- Center of Data Mining and Biomedical Informatics; Faculty of Medical Technology, Mahidol University; Bangkok 10700 Thailand
| | - Wiwat Owasirikul
- Center of Data Mining and Biomedical Informatics; Faculty of Medical Technology, Mahidol University; Bangkok 10700 Thailand
- Department of Radiological Technology; Faculty of Medical Technology, Mahidol University; Bangkok 10700 Thailand
| | - Napat Songtawee
- Center of Data Mining and Biomedical Informatics; Faculty of Medical Technology, Mahidol University; Bangkok 10700 Thailand
| | - Maris Lapins
- Department of Pharmaceutical Biosciences; Uppsala University; Uppsala Sweden
| | - Virapong Prachayasittikul
- Department of Clinical Microbiology and Applied Technology; Faculty of Medical Technology, Mahidol University; Bangkok 10700 Thailand
| | - Jarl E. S. Wikberg
- Department of Pharmaceutical Biosciences; Uppsala University; Uppsala Sweden
| |
Collapse
|
46
|
Arpino JAJ, Reddington SC, Halliwell LM, Rizkallah PJ, Jones DD. Random single amino acid deletion sampling unveils structural tolerance and the benefits of helical registry shift on GFP folding and structure. Structure 2014; 22:889-98. [PMID: 24856363 PMCID: PMC4058518 DOI: 10.1016/j.str.2014.03.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 03/08/2014] [Accepted: 03/10/2014] [Indexed: 12/01/2022]
Abstract
Altering a protein’s backbone through amino acid deletion is a common evolutionary mutational mechanism, but is generally ignored during protein engineering primarily because its effect on the folding-structure-function relationship is difficult to predict. Using directed evolution, enhanced green fluorescent protein (EGFP) was observed to tolerate residue deletion across the breadth of the protein, particularly within short and long loops, helical elements, and at the termini of strands. A variant with G4 removed from a helix (EGFPG4Δ) conferred significantly higher cellular fluorescence. Folding analysis revealed that EGFPG4Δ retained more structure upon unfolding and refolded with almost 100% efficiency but at the expense of thermodynamic stability. The EGFPG4Δ structure revealed that G4 deletion caused a beneficial helical registry shift resulting in a new polar interaction network, which potentially stabilizes a cis proline peptide bond and links secondary structure elements. Thus, deletion mutations and registry shifts can enhance proteins through structural rearrangements not possible by substitution mutations alone. Using directed evolution, the impact of amino acid deletion on EGFP is explored Loops, helices, and strand termini are especially tolerant to amino acid deletion A deletion mutant that enhances cellular production and fluorescence is identified Structure reveals that a helical registry shift creates a new polar network
Collapse
Affiliation(s)
- James A J Arpino
- School of Biosciences, Main Building, Park Place, Cardiff University, Cardiff CF10 3AT, UK
| | - Samuel C Reddington
- School of Biosciences, Main Building, Park Place, Cardiff University, Cardiff CF10 3AT, UK
| | - Lisa M Halliwell
- School of Biosciences, Main Building, Park Place, Cardiff University, Cardiff CF10 3AT, UK
| | - Pierre J Rizkallah
- School of Medicine, Cardiff University, WHRI, Main Building, Heath Park, Cardiff CF14 4XN, UK
| | - D Dafydd Jones
- School of Biosciences, Main Building, Park Place, Cardiff University, Cardiff CF10 3AT, UK.
| |
Collapse
|
47
|
Integrative refolding and purification of histidine-tagged protein by like-charge facilitated refolding and metal-chelate affinity adsorption. J Chromatogr A 2014; 1344:59-65. [DOI: 10.1016/j.chroma.2014.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 03/31/2014] [Accepted: 04/02/2014] [Indexed: 11/17/2022]
|
48
|
Troll CJ, Adhikary S, Cueff M, Mitra I, Eichman BF, Camps M. Interplay between base excision repair activity and toxicity of 3-methyladenine DNA glycosylases in an E. coli complementation system. Mutat Res 2014; 763-764:64-73. [PMID: 24709477 DOI: 10.1016/j.mrfmmm.2014.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 03/11/2014] [Accepted: 03/26/2014] [Indexed: 10/25/2022]
Abstract
DNA glycosylases carry out the first step of base excision repair by removing damaged bases from DNA. The N3-methyladenine (3MeA) DNA glycosylases specialize in alkylation repair and are either constitutively expressed or induced by exposure to alkylating agents. To study the functional and evolutionary significance of constitutive versus inducible expression, we expressed two closely related yeast 3MeA DNA glycosylases - inducible Saccharomyces cerevisiae MAG and constitutive S. pombe Mag1 - in a glycosylase-deficient Escherichia coli strain. In both cases, constitutive expression conferred resistance to alkylating agent exposure. However, in the absence of exogenous alkylation, high levels of expression of both glycosylases were deleterious. We attribute this toxicity to excessive glycosylase activity, since suppressing spMag1 expression correlated with improved growth in liquid culture, and spMag1 mutants exhibiting decreased glycosylase activity showed improved growth and viability. Selection of a random spMag1 mutant library for increased survival in the presence of exogenous alkylation resulted in the selection of hypomorphic mutants, providing evidence for the presence of a genetic barrier to the evolution of enhanced glycosylase activity when constitutively expressed. We also show that low levels of 3MeA glycosylase expression improve fitness in our glycosylase-deficient host, implying that 3MeA glycosylase activity is likely necessary for repair of endogenous lesions. These findings suggest that 3MeA glycosylase activity is evolutionarily conserved for repair of endogenously produced alkyl lesions, and that inducible expression represents a common strategy to rectify deleterious effects of excessive 3MeA activity in the absence of exogenous alkylation challenge.
Collapse
Affiliation(s)
- Christopher J Troll
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA
| | - Suraj Adhikary
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
| | - Marie Cueff
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA
| | - Ileena Mitra
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA
| | - Brandt F Eichman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
| | - Manel Camps
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA.
| |
Collapse
|
49
|
Gottipati K, Acholi S, Ruggli N, Choi KH. Autocatalytic activity and substrate specificity of the pestivirus N-terminal protease Npro. Virology 2014; 452-453:303-9. [PMID: 24606708 DOI: 10.1016/j.virol.2014.01.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 11/27/2013] [Accepted: 01/27/2014] [Indexed: 10/25/2022]
Abstract
Pestivirus N(pro) is the first protein translated in the viral polypeptide, and cleaves itself off co-translationally generating the N-terminus of the core protein. Once released, N(pro) blocks the host׳s interferon response by inducing degradation of interferon regulatory factor-3. N(pro׳)s intracellular autocatalytic activity and lack of trans-activity have hampered in vitro cleavage studies to establish its substrate specificity and the roles of individual residues. We constructed N(pro)-GFP fusion proteins that carry the authentic cleavage site and determined the autoproteolytic activities of N(pro) proteins containing substitutions at the predicted catalytic sites Glu22 and Cys69, at Arg100 that forms a salt bridge with Glu22, and at the cleavage site Cys168. Contrary to previous reports, we show that N(pro׳)s catalytic activity does not involve Glu22, which may instead be involved in protein stability. Furthermore, N(pro) does not have specificity for Cys168 at the cleavage site even though this residue is conserved throughout the pestivirus genus.
Collapse
Affiliation(s)
- Keerthi Gottipati
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555-0647, USA
| | - Sudheer Acholi
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555-0647, USA
| | - Nicolas Ruggli
- Institute of Virology and Immunology, CH-3147 Mittelhäusern, Switzerland
| | - Kyung H Choi
- Department of Biochemistry & Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX 77555-0647, USA.
| |
Collapse
|
50
|
Rosenman DJ, Huang YM, Xia K, Fraser K, Jones VE, Lamberson CM, Van Roey P, Colón W, Bystroff C. Green-lighting green fluorescent protein: faster and more efficient folding by eliminating a cis-trans peptide isomerization event. Protein Sci 2014; 23:400-10. [PMID: 24408076 DOI: 10.1002/pro.2421] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 01/02/2014] [Accepted: 01/06/2014] [Indexed: 11/06/2022]
Abstract
Wild-type green fluorescent protein (GFP) folds on a time scale of minutes. The slow step in folding is a cis-trans peptide bond isomerization. The only conserved cis-peptide bond in the native GFP structure, at P89, was remodeled by the insertion of two residues, followed by iterative energy minimization and side chain design. The engineered GFP was synthesized and found to fold faster and more efficiently than its template protein, recovering 50% more of its fluorescence upon refolding. The slow phase of folding is faster and smaller in amplitude, and hysteresis in refolding has been eliminated. The elimination of a previously reported kinetically trapped state in refolding suggests that X-P89 is trans in the trapped state. A 2.55 Å resolution crystal structure revealed that the new variant contains only trans-peptide bonds, as designed. This is the first instance of a computationally remodeled fluorescent protein that folds faster and more efficiently than wild type.
Collapse
Affiliation(s)
- David J Rosenman
- Rensselaer Polytechnic Institute, Biological Sciences, 110 8th St., Troy, New York, 12180
| | | | | | | | | | | | | | | | | |
Collapse
|