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Lee HC, Wonderly MP, Pokharel S, Strasburg GM, Marks BP, Fernando RH, Kang I. Cold‐batter mincing of hot‐boned and crust‐freeze‐air‐chilled ham muscle reduced fat content in protein gels. Int J Food Sci Technol 2020. [DOI: 10.1111/ijfs.14589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hong Chul Lee
- Department of Animal Science California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Morgan P. Wonderly
- Department of Animal Science California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Siroj Pokharel
- Department of Animal Science California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Gale M. Strasburg
- Department of Food Science & Human Nutrition Michigan State University East Lansing MI 48824 USA
| | - Bradley P. Marks
- Department of Biosystems & Agricultural Engineering Michigan State University East Lansing MI 48824 USA
| | - Raymond H. Fernando
- Department of Chemistry & Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Iksoon Kang
- Department of Animal Science California Polytechnic State University San Luis Obispo CA 93407 USA
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2
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Karmakar S, Chakraborty S, Gautam S, Chowdhury PK. Exploring the potency of the naturally occurring polyphenol curcumin as a probe for protein aggregation in crowded environments. Int J Biol Macromol 2019; 141:1088-1101. [DOI: 10.1016/j.ijbiomac.2019.09.049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/03/2019] [Accepted: 09/06/2019] [Indexed: 01/12/2023]
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3
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Rasouli S, Abdolvahabi A, Croom CM, Plewman DL, Shi Y, Ayers JI, Shaw BF. Lysine acylation in superoxide dismutase-1 electrostatically inhibits formation of fibrils with prion-like seeding. J Biol Chem 2017; 292:19366-19380. [PMID: 28974578 DOI: 10.1074/jbc.m117.805283] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/28/2017] [Indexed: 11/06/2022] Open
Abstract
The acylation of lysine residues in superoxide dismutase-1 (SOD1) has been previously shown to decrease its rate of nucleation and elongation into amyloid-like fibrils linked to amyotrophic lateral sclerosis. The chemical mechanism underlying this effect is unclear, i.e. hydrophobic/steric effects versus electrostatic effects. Moreover, the degree to which the acylation might alter the prion-like seeding of SOD1 in vivo has not been addressed. Here, we acylated a fraction of lysine residues in SOD1 with groups of variable hydrophobicity, charge, and conformational entropy. The effect of each acyl group on the rate of SOD1 fibril nucleation and elongation were quantified in vitro with thioflavin-T (ThT) fluorescence, and we performed 594 iterate aggregation assays to obtain statistically significant rates. The effect of the lysine acylation on the prion-like seeding of SOD1 was assayed in spinal cord extracts of transgenic mice expressing a G85R SOD1-yellow fluorescent protein construct. Acyl groups with >2 carboxylic acids diminished self-assembly into ThT-positive fibrils and instead promoted the self-assembly of ThT-negative fibrils and amorphous complexes. The addition of ThT-negative, acylated SOD1 fibrils to organotypic spinal cord failed to produce the SOD1 inclusion pathology that typically results from the addition of ThT-positive SOD1 fibrils. These results suggest that chemically increasing the net negative surface charge of SOD1 via acylation can block the prion-like propagation of oligomeric SOD1 in spinal cord.
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Affiliation(s)
- Sanaz Rasouli
- From the Department of Chemistry and Biochemistry and.,the Institute of Biomedical Studies, Baylor University, Waco, Texas 76706 and
| | | | | | | | - Yunhua Shi
- From the Department of Chemistry and Biochemistry and
| | - Jacob I Ayers
- the Department of Neuroscience, University of Florida, Gainesville, Florida 32611
| | - Bryan F Shaw
- From the Department of Chemistry and Biochemistry and
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4
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D'Addio SM, Bothe JR, Neri C, Walsh PL, Zhang J, Pierson E, Mao Y, Gindy M, Leone A, Templeton AC. New and Evolving Techniques for the Characterization of Peptide Therapeutics. J Pharm Sci 2016; 105:2989-3006. [DOI: 10.1016/j.xphs.2016.06.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 06/06/2016] [Accepted: 06/17/2016] [Indexed: 01/31/2023]
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5
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Coordination contributions to protein stability in metal-substituted carbonic anhydrase. J Biol Inorg Chem 2016; 21:659-67. [DOI: 10.1007/s00775-016-1375-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 06/20/2016] [Indexed: 10/21/2022]
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6
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Mittal S, Singh LR. Macromolecular crowding decelerates aggregation of a β-rich protein, bovine carbonic anhydrase: a case study. J Biochem 2014; 156:273-82. [PMID: 24917682 DOI: 10.1093/jb/mvu039] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The majority of in vitro investigations concerning protein aggregation have been performed in dilute systems, which poorly reflect the crowded in vivo scenario. Cell interior is highly crowded with soluble and insoluble macromolecules that alter macromolecular properties. Macromolecular crowding is known to enhance the rate and/or extent of protein aggregation. However, most of the understandings were derived from studies with α-rich or predominantly α-proteins. Indeed, α-proteins fold faster than β-proteins and conversion of α-helices to cross β-sheets are responsible for aggregate/amyloid formation. Therefore, it is important to investigate how macromolecular crowding affects the aggregation propensity of β-rich proteins. In this study, we investigated the effect of synthetic macromolecular crowders on bovine carbonic anhydrase (BCA, a β-rich protein) aggregation. In contrast to the effect of macromolecular crowding on α-rich proteins, BCA aggregation was observed to be reduced due to decrease in the population of aggregation-prone intermediates as a consequence of increased native state stability. In addition, the extent of aggregation was found to depend on the nature of the crowder under consideration. Combining the published data on α-proteins and this study, we conclude that macromolecular crowding can have opposite consequences on protein aggregation process depending on the fold type of the protein.
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Affiliation(s)
- Shruti Mittal
- Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, North Campus, New Delhi 110 007, India
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7
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Qadeer A, Ahmad E, Zaman M, Khan MW, Khan JM, Rabbani G, Tarique KF, Sharma G, Gourinath S, Nadeem S, Badr G, Khan RH. Concentration-dependent antagonistic persuasion of SDS and naphthalene derivatives on the fibrillation of stem bromelain. Arch Biochem Biophys 2013; 540:101-16. [DOI: 10.1016/j.abb.2013.10.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 10/11/2013] [Accepted: 10/21/2013] [Indexed: 12/01/2022]
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8
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Tomar R, Garg DK, Mishra R, Thakur AK, Kundu B. N-terminal domain ofPyrococcus furiosusl-asparaginase functions as a non-specific, stable, molecular chaperone. FEBS J 2013; 280:2688-99. [DOI: 10.1111/febs.12271] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 03/25/2013] [Accepted: 03/27/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Rachana Tomar
- Kusuma School of Biological Sciences; Indian Institute of Technology Delhi; New Delhi; India
| | - Dushyant K. Garg
- Kusuma School of Biological Sciences; Indian Institute of Technology Delhi; New Delhi; India
| | - Rahul Mishra
- Department of Biological Sciences and Bioengineering; Indian Institute of Technology Kanpur; India
| | - Ashwani K. Thakur
- Department of Biological Sciences and Bioengineering; Indian Institute of Technology Kanpur; India
| | - Bishwajit Kundu
- Kusuma School of Biological Sciences; Indian Institute of Technology Delhi; New Delhi; India
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9
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Makwana PK, Jethva PN, Roy I. Coumarin 6 and 1,6-diphenyl-1,3,5-hexatriene (DPH) as fluorescent probes to monitor protein aggregation. Analyst 2011; 136:2161-7. [PMID: 21445407 DOI: 10.1039/c0an00829j] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the use of Coumarin 6 and 1,6-diphenyl-1,3,5-hexatriene (DPH) for the identification of protein aggregates for the first time. The two dyes can be used at very low (nanomolar) concentrations and do not interfere with the aggregation process, as is reported for other commonly used fluorescent protein probes. In the presence of protein aggregates, their quantum yields are significantly high. DPH is able to recognize both amorphous and fibrillar aggregates but cannot distinguish between them. Coumarin 6 can distinguish between both types of aggregates. It also exhibits the characteristic sigmoidal curve of amyloid formation, with higher sensitivity for detection of fibrillation than the conventionally used Thioflavin T.
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Affiliation(s)
- Pinakin K Makwana
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Punjab, India
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10
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Hawe A, Filipe V, Jiskoot W. Fluorescent molecular rotors as dyes to characterize polysorbate-containing IgG formulations. Pharm Res 2009; 27:314-26. [PMID: 20041280 PMCID: PMC2812426 DOI: 10.1007/s11095-009-0020-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 11/24/2009] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim was to evaluate fluorescent molecular rotors (DCVJ and CCVJ), which are mainly sensitive to viscosity, for the characterization of polysorbate-containing IgG formulations and compare them to the polarity-sensitive dyes ANS, Bis-ANS and Nile Red. METHODS IgG formulations with polysorbate 20 or 80 were stressed below the aggregation temperature and analyzed by steady-state and time-resolved fluorescence and by HP-SEC with UV and fluorescent dye detection (Bis-ANS and CCVJ). Furthermore, commercial protein preparations of therapeutic proteins (Enbrel 50 mg, Humira 40 mg and MabThera 100 mg) were aggregated accordingly and analyzed with CCVJ fluorescence and HP-SEC. RESULTS Contrarily to (Bis-)ANS and Nile Red, the molecular rotors DCVJ and CCVJ showed low background fluorescence in polysorbate-containing buffers. Time-resolved fluorescence experiments confirmed the steady-state fluorescence data. Both DCVJ and CCVJ showed enhanced fluorescence intensity for aggregated IgG formulations and were suitable for the characterization of polysorbate-containing IgG formulations in steady-state fluorescence and HP-SEC with dye detection (CCVJ). CCVJ was capable of detecting thermally induced aggregation in the commercial polysorbate-containing products Enbrel 50 mg, Humira 40 mg and MabThera 100 mg. CONCLUSION Fluorescent molecular rotors are suitable probes to detect aggregation in polysorbate-containing IgG formulations.
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Affiliation(s)
- Andrea Hawe
- Division of Drug Delivery Technology, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands.
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11
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Mahler HC, Friess W, Grauschopf U, Kiese S. Protein aggregation: pathways, induction factors and analysis. J Pharm Sci 2009; 98:2909-34. [PMID: 18823031 DOI: 10.1002/jps.21566] [Citation(s) in RCA: 614] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Control and analysis of protein aggregation is an increasing challenge to pharmaceutical research and development. Due to the nature of protein interactions, protein aggregation may occur at various points throughout the lifetime of a protein and may be of different quantity and quality such as size, shape, morphology. It is therefore important to understand the interactions, causes and analyses of such aggregates in order to control protein aggregation to enable successful products. This review gives a short outline of currently discussed pathways and induction methods for protein aggregation and describes currently employed set of analytical techniques and emerging technologies for aggregate detection, characterization and quantification. A major challenge for the analysis of protein aggregates is that no single analytical method exists to cover the entire size range or type of aggregates which may appear. Each analytical method not only shows its specific advantages but also has its limitations. The limits of detection and the possibility of creating artifacts through sample preparation by inducing or destroying aggregates need to be considered with each method used. Therefore, it may also be advisable to carefully compare analytical results of orthogonal methods for similar size ranges to evaluate method performance.
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Affiliation(s)
- Hanns-Christian Mahler
- Formulation R&D Biologics, Pharmaceutical and Analytical R&D, F. Hoffmann-La Roche Ltd., Basel, Switzerland.
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12
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Hawe A, Sutter M, Jiskoot W. Extrinsic fluorescent dyes as tools for protein characterization. Pharm Res 2008; 25:1487-99. [PMID: 18172579 PMCID: PMC2440933 DOI: 10.1007/s11095-007-9516-9] [Citation(s) in RCA: 856] [Impact Index Per Article: 53.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Accepted: 12/05/2007] [Indexed: 11/16/2022]
Abstract
Noncovalent, extrinsic fluorescent dyes are applied in various fields of protein analysis, e.g. to characterize folding intermediates, measure surface hydrophobicity, and detect aggregation or fibrillation. The main underlying mechanisms, which explain the fluorescence properties of many extrinsic dyes, are solvent relaxation processes and (twisted) intramolecular charge transfer reactions, which are affected by the environment and by interactions of the dyes with proteins. In recent time, the use of extrinsic fluorescent dyes such as ANS, Bis-ANS, Nile Red, Thioflavin T and others has increased, because of their versatility, sensitivity and suitability for high-throughput screening. The intention of this review is to give an overview of available extrinsic dyes, explain their spectral properties, and show illustrative examples of their various applications in protein characterization.
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Affiliation(s)
- Andrea Hawe
- Division of Drug Delivery Technology, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Marc Sutter
- Division of Drug Delivery Technology, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
- Novartis Pharma AG, WSJ-316.4.14, CH-4056 Basel, Switzerland
| | - Wim Jiskoot
- Division of Drug Delivery Technology, Leiden/Amsterdam Center for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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13
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Krishnamurthy VM, Kaufman GK, Urbach AR, Gitlin I, Gudiksen KL, Weibel DB, Whitesides GM. Carbonic anhydrase as a model for biophysical and physical-organic studies of proteins and protein-ligand binding. Chem Rev 2008; 108:946-1051. [PMID: 18335973 PMCID: PMC2740730 DOI: 10.1021/cr050262p] [Citation(s) in RCA: 555] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Vijay M. Krishnamurthy
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - George K. Kaufman
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - Adam R. Urbach
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - Irina Gitlin
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - Katherine L. Gudiksen
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - Douglas B. Weibel
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
| | - George M. Whitesides
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138
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14
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Sharma S, Guptasarma P. Evidence of native-like substructure(s) in polypeptide chains of carbonic anhydrase deposited into insoluble aggregates during thermal unfolding. Protein J 2007; 27:50-8. [PMID: 17882537 DOI: 10.1007/s10930-007-9107-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A non-specific protease, subtilisin, was used to probe the existence of folded structure in thermal aggregates of bovine carbonic anhydrase-II (BCA). BCA aggregates and native BCA were subjected to proteolysis and electrophoretic analyses which revealed the accumulation of polypeptide fragments of similar size, indicating survival of similar sections of folded structure burying peptide bonds away from scission in the two samples. N-terminal sequencing revealed that the termini of size-matched fragments from the two samples were either identical, or located very close to each other, and predominantly on the surface of the 3-dimensional structure of native BCA. The susceptibility to proteolysis of very nearly the same sites in the two samples suggests that native-like elements of structure survive within BCA aggregates. The finding that thermal aggregation can involve interactions among molecules retaining elements of native-like structure, suggests that complete chain unfolding may not be a necessary prerequisite for all aggregation.
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Affiliation(s)
- Swati Sharma
- Institute of Microbial Technology, Chandigarh, 160 036, India
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15
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Kerby MB, Lee J, Ziperstein J, Tripathi A. Kinetic measurements of protein conformation in a microchip. Biotechnol Prog 2007; 22:1416-25. [PMID: 17022682 DOI: 10.1021/bp060111n] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper presents a microchip-based system for collecting kinetic time-based information on protein refolding and unfolding. Dynamic protein conformational change pathways were studied in microchannel flow using a microfluidic device. We present a protein-conserving approach for quantifying refolding by dynamically varying the concentration of the chemical denaturants, guanidine hydrochloride and urea. Short diffusion distances in the microchannel result in rapid equilibrium between protein and titrating solutions. Dilutions on the chip were tightly regulated using pressure controls rather than syringe-based flow, as verified with extensive on-chip tracer dye controls. To validate this protein assay method, folding transition experiments were performed using two well-characterized proteins, human serum albumin (HSA) and bovine carbonic anhydrase (BCA). Transition events were monitored through fluorescence intensity shifts of the protein dye 8-anilino-1-naphthalenesulfonic acid (ANS) during dilutions of protein from urea or guanidine hydrochloride solutions. The enzymatic activity of refolded BCA was measured by UV absorption through the conversion of p-nitrophenyl acetate (p-NPA). The microchip protein refolding transitions using ANS were well-correlated with conventional plate-based experiments. The microfluidic platform enables refolding studies to identify rapidly the optimal folding strategy for a protein using small quantities of material.
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Affiliation(s)
- Matthew B Kerby
- Biomedical Engineering and Chemical and Biochemical Engineering, Biochemical Engineering Laboratory, Division of Engineering, Brown University, Providence Rhode Island 02912, USA
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16
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Technical note: A simplified procedure for myofibril hydrophobicity determination. Meat Sci 2006; 74:681-3. [DOI: 10.1016/j.meatsci.2006.05.019] [Citation(s) in RCA: 269] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2006] [Revised: 05/16/2006] [Accepted: 05/16/2006] [Indexed: 11/22/2022]
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17
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Pedersen S, Nesgaard L, Baptista RP, Melo EP, Kristensen SR, Otzen DE. pH-dependent aggregation of cutinase is efficiently suppressed by 1,8-ANS. Biopolymers 2006; 83:619-29. [PMID: 16964599 DOI: 10.1002/bip.20598] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have studied the thermal stability of the triglyceride-hydrolyzing enzyme cutinase from F. solani pisi at pH values straddling the pI (pH 8.0). At the pI, increasing the protein concentration from 5 to 80 microM decreases the apparent melting temperature by 19 degrees C. This effect vanishes at pH values more than one unit away from pI. In contrast to additives such as detergents and osmolytes, the hydrophobic fluorophore 1,8-ANS completely and saturably suppresses this effect, restoring 70% of enzymatic activity upon cooling. ANS binds strongly to native cutinase as a noncompetitive inhibitor with up to 5 ANS per cutinase molecule. Only the first ANS molecule stabilizes cutinase; however, the last 4 ANS molecules decrease Tm by up to 7 degrees C. Similar pI-dependent aggregation and suppression by ANS is observed for T. lanuginosus lipase, but not for lysozyme or porcine alpha-amylase, suggesting that this behavior is most prevalent for proteins with affinity for hydrophobic substrates and consequent exposure of hydrophobic patches. Aggregation may be promoted by a fluctuating ensemble of native-like states associating via intermolecular beta-sheet rich structures unless blocked by ANS. Our data highlight the chaperone activity of small molecules with affinity for hydrophobic surfaces and their potential application as stabilizers at appropriate stoichiometries.
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Affiliation(s)
- Shona Pedersen
- Department of Life Sciences, Aalborg University, DK-9000 Aalborg, Denmark
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18
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Grover A, Dugar D, Kundu B. Predicting alternate structure attainment and amyloidogenesis: a nonlinear signal analysis approach. Biochem Biophys Res Commun 2005; 338:1410-6. [PMID: 16263079 DOI: 10.1016/j.bbrc.2005.10.104] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Accepted: 10/07/2005] [Indexed: 11/20/2022]
Abstract
Chain hydrophobicity values have been used in prediction of alternate structure attainment by a polypeptide. Nonlinear signal analysis on the hydrophobicity values gives important clues about the propensities of particular stretches of a protein to form local or nonlocal contacts. These contacts determine the folding behavior of a polypeptide and helps in predicting the final structure that can be attained. A nonlinear signal analysis called the recurrent quantification analysis has been carried out using the hydrophobicity values on a wide range of proteins obtained from human, plant, and fungal sources. Here, we show that such an analysis gives us an easy handle in determining sequences within the proteins that may be important in beta-sheet formation leading to amyloidosis.
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Affiliation(s)
- Abhinav Grover
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India
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19
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Wyman AJ, Yocum CF. Assembly and function of the photosystem II manganese stabilizing protein: lessons from its natively unfolded behavior. PHOTOSYNTHESIS RESEARCH 2005; 84:283-8. [PMID: 16049787 DOI: 10.1007/s11120-004-7759-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Accepted: 12/16/2004] [Indexed: 05/03/2023]
Abstract
The Photosystem II (PS II) manganese stabilizing protein (MSP) possesses characteristics, including thermostability, ascribed to the natively unfolded class of proteins (Lydakis-Simantiris et al. (1999) Biochemistry 38: 404-414). A site-directed mutant of MSP, C28A, C51A, which lacks the -S-S- bridge, also binds to PS II at wild-type levels and reconstitutes oxygen evolution activity [Betts et al. (1996) Biochim Biophys Acta 1274: 135-142], although the mutant protein is even more disordered in solution. Both WT and C28A, C51A MSP aggregate upon heating, but an examination of the effects of protein concentration and pH on heat-induced aggregation showed that each MSP species exhibited greater resistance to aggregation at a pH near their pI (5.2) than do either bovine serum albumin (BSA) or carbonic anhydrase, which were used as model water soluble proteins. Increases in pH above the pI of the MSPs and BSA enhanced their aggregation resistance, a behavior which can be predicted from their charge (MSP) or a combination of charge and stabilization by -S-S- bonds (BSA). In the case of aggregation resistance by MSP, this is likely to be an important factor in its ability to avoid unproductive self-association reactions in favor of formation of the protein-protein interactions that lead to formation of the functional oxygen evolving complex.
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Affiliation(s)
- Aaron J Wyman
- Department of Molecular, Cellular, and Developmental Biology, The University of Michigan-Ann Arbor, MI 48109, USA
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20
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Fu X, Zhang X, Chang Z. 4,4'-Dianilino-1,1'-binaphthyl-5,5'-sulfonate, a novel molecule having chaperone-like activity. Biochem Biophys Res Commun 2005; 329:1087-93. [PMID: 15752765 DOI: 10.1016/j.bbrc.2005.01.164] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2005] [Indexed: 11/24/2022]
Abstract
4,4'-Dianilino-1,1'-binaphthyl-5,5'-sulfonate (bis-ANS) and 1-anilinonaphthalene-8-sulfonate (ANS) are hydrophobic probes that are widely used in protein folding studies, using their capacity to bind to hydrophobic regions of partially unfolded proteins and in turn leading to an increase in fluorescence. Here we reveal a novel chaperone-like activity for bis-ANS, which acted as a highly effective inhibitor for the thermal- or chemical-induced aggregation of alcohol dehydrogenase, insulin or the whole cell extract of Escherichia coli, with ANS showing a much weaker effect. The studies to elucidate the mechanism underlying this activity show that bis-ANS is able to form stable soluble aggregates with the denaturing proteins and dramatically increase its fluorescence intensity upon incubation with aggregation-prone proteins. Moreover, we found that bis-ANS is able to prevent the heat inactivation of citrate synthase. These observations suggest that bis-ANS is able to block the exposed hydrophobic surfaces to suppress protein aggregation, acting in a way similar to what small heat shock proteins (one sub-class of molecular chaperones) do. The data presented here, together with the report that bis-ANS was able to suppress the amyloid formation of the prion peptide [J. Biol. Chem. 279 (2004) 5346], suggest that this molecule may be used as a potential protein stabilizer in addition to its current application as a hydrophobic probe.
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Affiliation(s)
- Xinmiao Fu
- State Key Laboratory of Protein Engineering and Plant Genetic Engineering, Peking University, Beijing 100871, China
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21
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Edkins AL, Ludewig MH, Blatch GL. A Trypanosoma cruzi heat shock protein 40 is able to stimulate the adenosine triphosphate hydrolysis activity of heat shock protein 70 and can substitute for a yeast heat shock protein 40. Int J Biochem Cell Biol 2005; 36:1585-98. [PMID: 15147737 DOI: 10.1016/j.biocel.2004.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2003] [Revised: 01/13/2004] [Accepted: 01/22/2004] [Indexed: 11/23/2022]
Abstract
The process of assisted protein folding, characteristic of members of the heat shock protein 70 (Hsp70) and heat shock protein 40 (Hsp40) molecular chaperone families, is important for maintaining the structural integrity of cellular protein machinery under normal and stressful conditions. Hsp70 and Hsp40 cooperate to bind non-native protein conformations in a process of adenosine triphosphate (ATP)-regulated assisted protein folding. We have analysed the molecular chaperone activity of the cytoplasmic inducible Hsp70 from Trypanosoma cruzi (TcHsp70) and its interactions with its potential partner Hsp40s (T. cruzi DnaJ protein 1 [Tcj1] and T. cruzi DnaJ protein 2 [Tcj2]). Histidine-tagged TcHsp70 (His-TcHsp70), Tcj1 (Tcj1-His) and Tcj2 (His-Tcj2) were over-produced in Escherichia coli and purified by nickel affinity chromatography. The in vitro basal specific ATP hydrolysis activity (ATPase activity) of His-TcHsp70 was determined as 40 nmol phosphate/min/mg protein, significantly higher than that reported for other Hsp70s. The basal specific ATPase activity was stimulated to a maximal level of 60 nmol phosphate/min/mg protein in the presence of His-Tcj2 and a model substrate, reduced carboxymethylated alpha-lactalbumin. In vivo complementation assays showed that Tcj2 was able to overcome the temperature sensitivity of the ydj1 mutant Saccharomyces cerevisiae strain JJ160, suggesting that Tcj2 may be functionally equivalent to the yeast Hsp40 homologue (yeast DnaJ protein 1, Ydj1). These data suggest that Tcj2 is involved in cytoprotection in a similar fashion to Ydj1, and that TcHsp70 and Tcj2 may interact in a nucleotide-regulated process of chaperone-assisted protein folding.
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Affiliation(s)
- Adrienne L Edkins
- Department of Biochemistry, Microbiology & Biotechnology, Rhodes University, Grahamstown 6140, South Africa
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22
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Rauceo JM, Gaur NK, Lee KG, Edwards JE, Klotz SA, Lipke PN. Global cell surface conformational shift mediated by a Candida albicans adhesin. Infect Immun 2004; 72:4948-55. [PMID: 15321986 PMCID: PMC517415 DOI: 10.1128/iai.72.9.4948-4955.2004] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida albicans maintains both commensal and pathogenic states in humans. Both states are dependent on cell surface-expressed adhesins, including those of the Als family. Heterologous expression of Als5p at the surface of Saccharomyces cerevisiae results in Als5p-mediated adhesion to various ligands, followed by formation of multicellular aggregates. Following adhesion of one region of the cell to fibronectin-coated beads, the entire surface of the cells became competent to mediate cell-cell aggregation. Aggregates formed in the presence of metabolic inhibitors or signal transduction inhibitors but were reduced in the presence of 8-anilino-1-naphthalene-sulfonic acid (ANS) or Congo Red (CR), perturbants that inhibit protein structural transitions. These perturbants also inhibited aggregation of C. albicans. An increase in ANS fluorescence, which accompanied Als-dependent cellular adhesion, indicated an increase in cell surface hydrophobicity. In addition, C. albicans and Als5p-expressing S. cerevisiae showed an aggregation-induced birefringence indicative of order on the cell surface. The increase in birefringence did not occur in the presence of the aggregation disruptants ANS and CR. These results suggest a model for Als5p-mediated aggregation in which an adhesion-triggered change in the conformation of Als5p propagates around the cell surface, forming ordered aggregation-competent regions.
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Affiliation(s)
- Jason M Rauceo
- Department of Biology, Hunter College, 695 Park Ave., New York, NY 10021, USA
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23
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Kundu B, Shukla A, Chaba R, Guptasarma P. The excised heat-shock domain of αB crystallin is a folded, proteolytically susceptible trimer with significant surface hydrophobicity and a tendency to self-aggregate upon heating. Protein Expr Purif 2004; 36:263-71. [PMID: 15249049 DOI: 10.1016/j.pep.2004.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2004] [Revised: 03/30/2004] [Indexed: 10/26/2022]
Abstract
The lens protein, alpha-crystallin, is a molecular chaperone that prevents the thermal aggregation of other proteins. The C-terminal domain of this protein (homologous to domains present in small heat-shock proteins) is implicated in chaperone function, although the domain itself has been reported to show no chaperone activity. Here, we show that the domain can be excised out of the intact alphaB polypeptide and recovered directly in pure form through the transfer of CNBr digests of whole lens homogenates into urea-containing buffer, followed by dialysis-based refolding of digests under acidic conditions and a single gel-filtration purification step. The folded (beta sheet) domain thus obtained is found to be (a) predominantly trimeric, and to display (b) significant surface hydrophobicity, (c) a marked tendency to undergo degradation, and (d) a tendency to aggregate upon heating, and on exposure to UV light. Thus, the twin 'chaperone' features of multimericity and surface hydrophobicity are clearly seen to be insufficient for this domain to function as a chaperone. Since alpha-crystallin interacts with its substrates through hydrophobic interactions, the hydrophobicity of the excised domain indicates that separation of domains may regulate function; at the same time, the fact is also highlighted that surface hydrophobicity is a liability in a chaperone since heating strengthens hydrophobic interactions and can potentially promote self-aggregation. Thus, it would appear that the role of the N-terminal domain in alpha-crystallin is to facilitate the creation of a porous, hollow structural framework of >/=24 subunits in which solubility is effected through increase in the ratio of exposed surface area to buried volume. Trimers of interacting C-terminal domains anchored to this superstructure, and positioned within its interior, might allow hydrophobic surfaces to remain accessible to substrates without compromising solubility.
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Affiliation(s)
- Bishwajit Kundu
- Institute of Microbial Technology, Sector 39-A, Chandigarh-160 036, India
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24
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Bertsch M, Mayburd AL, Kassner RJ. The identification of hydrophobic sites on the surface of proteins using absorption difference spectroscopy of bromophenol blue. Anal Biochem 2003; 313:187-95. [PMID: 12605855 DOI: 10.1016/s0003-2697(02)00590-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Hydrophobic sites on the surface of protein molecules are thought to have important functional roles. The identification of such sites can provide information about the function and mode of interaction with other cellular components. While the fluorescence enhancement of polarity-sensitive dyes has been useful in identifying hydrophobic sites on a number of targets, strong intrinsic quenching of Nile red and ANSA dye fluorescence is observed on binding to a cytochrome c('). Fluorescence quenching is also observed to take place in the presence of a variety of other biologically important molecules which can compromise the quantitative determination of binding constants. Absorption difference spectroscopy is shown not to be sensitive to the presence of fluorescence quenchers but sensitive enough to measure binding constants. The dye BPB is shown to bind to the same hydrophobic sites on proteins as polarity-sensitive fluorescence probes. The absorption spectrum of BPB is also observed to be polarity sensitive. A binding constant of 3x10(6)M(-1) for BPB to BSA has been measured by absorption difference spectroscopy. An empirical correlation is observed between the shape of the absorption difference spectrum of BPB and the polarity of the environment. The results indicate that absorption difference spectroscopy of BPB provides a valuable supplement to fluorescence for determining the presence of hydrophobic sites on the surface of proteins as well as a method for measuring binding constants.
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Affiliation(s)
- M Bertsch
- Department of Chemistry, University of Illinois at Chicago, Science and Engineering South 845 West Taylor Street, Rm. 4500, Chicago, IL 60607, USA
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25
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Kundu B, Shukla A, Guptasarma P. Peptide scanning-based identification of regions of gamma-II crystallin involved in thermal aggregation: evidence of the involvement of structurally analogous, helix-containing loops from the two double Greek key domains of the molecule. Arch Biochem Biophys 2003; 410:69-75. [PMID: 12559977 DOI: 10.1016/s0003-9861(02)00676-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gamma crystallin is one of three structural proteins present in great abundance in the fiber cells of the vertebrate eye lens. The protein displays a tendency to aggregate readily in the course of heating, cooling, being exposed to ultraviolet radiation, or rapid refolding. To investigate the molecular mechanisms underlying such aggregation, we have employed a peptide-scanning approach aimed at identifying regions of bovine gamma-II crystallin that may be involved in intermolecular interactions leading to aggregation, using assays that measure the competitive inhibition of such aggregation by reagents drawn from a group of contiguous (overlapping) peptides derived from the sequence of the protein itself. Our results suggest that two regions, comprising residues 61-74, and 145-159, play key roles in aggregative interactions. Intriguingly, the two regions (each containing a solvent-exposed, single-turn helix in the native structure) are located in structurally analogous positions in the two homologous double Greek key (beta sheet) domains of the protein, suggesting that helix-strand conversions may operate to facilitate intermolecular beta sheet interactions during aggregation.
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Affiliation(s)
- Bishwajit Kundu
- Institute of Microbial Technology, Sector 39-A, Chandigarh 160 036, India
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26
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Kundu B, Guptasarma P. Use of a hydrophobic dye to indirectly probe the structural organization and conformational plasticity of molecules in amorphous aggregates of carbonic anhydrase. Biochem Biophys Res Commun 2002; 293:572-7. [PMID: 12054640 DOI: 10.1016/s0006-291x(02)00257-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Understanding protein aggregation may hold important clues to understanding what goes wrong with protein folding in neurodegenerative disorders and in bioreactors in which proteins are overexpressed. Unfortunately, aggregates tend to be intractable to most standard methods of biochemical investigation. Thus, relatively little is even now known about the micro- and macro-structural features of aggregates. To gain insights into the thermal aggregation of a model globular protein [bovine carbonic anhydrase (BCA)], we have used spectrofluorimetry to examine the binding of a hydrophobic dye, 8-anilinonaphthalene sulfonate (ANS), to hydrophobic clusters on the protein's surface both before and after heat-induced aggregation and upon cooling. Whereas native BCA shows no surface hydrophobicity, thermally aggregated BCA displays significant hydrophobicity both in the heated state and upon cooling. The timing of the addition of ANS in the course of aggregation makes no net difference to the ANS bound; we argue that this suggests that aggregates are essentially porous. Cooling of aggregates results in a dramatic, fully reversible increase in ANS binding that cannot be explained by the temperature dependence of fluorescence quantum yield alone; we argue that the enhancement of fluorescence upon cooling indicates possible structural consolidation of unfolded regions within aggregates (akin to refolding), with the required structural reorganization being facilitated by porosity. Finally, implications of porosity in aggregates are discussed, in particular, for the possible immobilization of enzymes through fusion with aggregation-prone protein domains.
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Affiliation(s)
- Bishwajit Kundu
- Institute of Microbial Technology, Sector 39-A, Chandigarh 160 036, India
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27
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Kundu B, Shukla A, Guptasarma P. Manipulation of unfolding-induced protein aggregation by peptides selected for aggregate-binding ability through phage display library screening. Biochem Biophys Res Commun 2002; 291:903-7. [PMID: 11866450 DOI: 10.1006/bbrc.2002.6549] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A phage-displayed library of peptides (12-mer) was screened for the ability to bind to thermally aggregated bovine carbonic anhydrase (BCA), with a view toward examining whether peptides possessing this ability might bind to partially structured intermediates on the protein's unfolding pathway and, therefore, constitute useful tools for manipulation of the kinetic partitioning of molecules between the unfolded and aggregated states. Two peptides [N-HPSTMGLRTMHP-C and N-TPSAWKTALVKA-C] were identified and tested. While neither showed thermal aggregation autonomously, both peptides individually elicited remarkable increases in the levels of thermal aggregation of BCA. A possible explanation is that both peptides bind to surfaces on molten BCA that are not directly involved in aggregation. Such binding could slow down interconversions between folded and unfolded states and stabilize aggregation-prone intermediate(s) to make them more prone to aggregation, while failing to achieve any steric prevention of aggregation. The approach has the potential of yielding useful aggregation-aiding/inhibiting agents, and may provide clues to whether amorphous aggregates are "immobilized" forms of folding intermediates.
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Affiliation(s)
- Bishwajit Kundu
- Institute of Microbial Technology, Sector 39-A, Chandigarh, India
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28
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Bismuto E, Gratton E, Lamb DC. Dynamics of ANS binding to tuna apomyoglobin measured with fluorescence correlation spectroscopy. Biophys J 2001; 81:3510-21. [PMID: 11721012 PMCID: PMC1301806 DOI: 10.1016/s0006-3495(01)75982-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The dynamics of the binding reaction of ANS to native and partly folded (molten globule) tuna and horse apomyoglobins has been investigated by fluorescence correlation spectroscopy and frequency domain fluorometry. The reaction rate has been measured as a function of apomyoglobin and ANS concentrations, pH, and temperature. Examination of the autocorrelation functions shows that the reaction rate is fast enough to be observed in tuna apomyoglobin, whereas the reaction rate in horse apomyoglobin is on the same time scale as diffusion through the volume or longer. Specifically, for tuna apomyoglobin at pH 7 and room temperature the on rate is 2200 microM(-1) s(-1) and the off rate is 5900 s(-1), in comparison with k(on) = 640 microM(-1) s(-1) and k(off) = 560 s(-1) for horse myoglobin as measured previously. The independence of the reaction rate from the ANS concentration indicates that the reaction rate is dominated by the off rate. The temperature dependence of the on-rate shows that this rate is diffusion limited. The temperature dependence of the off rates analyzed by Arrhenius and Ferry models indicates that the off rate depends on the dynamics of the protein. The differences between horse and tuna apomyoglobins in the ANS binding rate can be explained in terms of the three-dimensional apoprotein structures obtained by energy minimization after heme removal starting from crystallographic coordinates. The comparison of the calculated apomyoglobin surfaces shows a 15% smaller cavity for tuna apomyoglobin. Furthermore, a negative charge (D44) is present in the heme cavity of tuna apomyoglobin that could decrease the strength of ANS binding. At pH 5 the fluorescence lifetime distribution of ANS-apomyoglobin is bimodal, suggesting the presence of an additional binding site in the protein. The binding rates determined by FCS under these conditions show that the protein is either in the open configuration or is more flexible, making it much easier to bind. At pH 3, the protein is in a partially denatured state with multiple potential binding sites for ANS molecule, and the interpretation of the autocorrelation function is not possible by simple models. This conclusion is consistent with the broad distribution of ANS fluorescence lifetimes observed in frequency domain measurements.
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Affiliation(s)
- E Bismuto
- Departimento di Biochimica e Biofisica, Seconda Universita di Napoli, 80138 Napoli, Italy.
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29
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Mizejewski GJ. Alpha-fetoprotein structure and function: relevance to isoforms, epitopes, and conformational variants. Exp Biol Med (Maywood) 2001; 226:377-408. [PMID: 11393167 DOI: 10.1177/153537020122600503] [Citation(s) in RCA: 173] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Mammalian alpha-fetoprotein (AFP) is classified as a member of the albuminoid gene superfamily consisting of albumin, AFP, vitamin D (Gc) protein, and alpha-albumin. Molecular variants of AFP have long been reported in the biomedical literature. Early studies identified isoelectric pH isoforms and lectin-binding variants of AFP, which differed in their physicochemical properties, but not in amino acid composition. Genetic variants of AFP, differing in mRNA kilobase length, were later extensively described in rodent models during fetal/perinatal stages, carcinogenesis, and organ regeneration. With the advent of monoclonal antibodies in the early 1980s, multiple antigenic epitopes on native AFP were detected and categorized, culminating in the identification of six to seven major epitopes. During this period, various AFP-binding proteins and receptors were reported to inhibit certain AFP immunoreactions. Concomittantly, human and rodent AFP were cloned and the amino acid sequences of the translated proteins were divulged. Once the amino acid composition of the AFP molecule was known, enzymatic fragments could be identified and synthetic peptide segments synthesized. Following discovery of the molten globule form in 1981, the existence of transitory, intermediate forms of AFP were acknowledged and their physiological significance was realized. In the present review, the various isoforms and variants of AFP are discussed in light of their potential biological relevance.
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Affiliation(s)
- G J Mizejewski
- Division of Molecular Medicine, Wadsworth Center, New York State Department of Health, Albany 12201, USA.
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30
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Eggers DK, Valentine JS. Molecular confinement influences protein structure and enhances thermal protein stability. Protein Sci 2001; 10:250-61. [PMID: 11266611 PMCID: PMC2373941 DOI: 10.1110/ps.36201] [Citation(s) in RCA: 291] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The sol-gel method of encapsulating proteins in a silica matrix was investigated as a potential experimental system for testing the effects of molecular confinement on the structure and stability of proteins. We demonstrate that silica entrapment (1) is fully compatible with structure analysis by circular dichroism, (2) allows conformational studies in contact with solvents that would otherwise promote aggregation in solution, and (3) generally enhances thermal protein stability. Lysozyme, alpha-lactalbumin, and metmyoglobin retained native-like solution structures following sol-gel encapsulation, but apomyoglobin was found to be largely unfolded within the silica matrix under control buffer conditions. The secondary structure of encapsulated apomyoglobin was unaltered by changes in pH and ionic strength of KCl. Intriguingly, the addition of other neutral salts resulted in an increase in the alpha-helical content of encapsulated apomyoglobin in accordance with the Hofmeister ion series. We hypothesize that protein conformation is influenced directly by the properties of confined water in the pores of the silica. Further work is needed to differentiate the steric effects of the silica matrix from the solvent effects of confined water on protein structure and to determine the extent to which this experimental system mimics the effects of crowding and confinement on the function of macromolecules in vivo.
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Affiliation(s)
- D K Eggers
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
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