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Rockwell NC, Lagarias JC. Cyanobacteriochromes from Gloeobacterales Provide New Insight into the Diversification of Cyanobacterial Photoreceptors. J Mol Biol 2024; 436:168313. [PMID: 37839679 DOI: 10.1016/j.jmb.2023.168313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/15/2023] [Accepted: 10/10/2023] [Indexed: 10/17/2023]
Abstract
The phytochrome superfamily comprises three groups of photoreceptors sharing a conserved GAF (cGMP-specific phosphodiesterases, cyanobacterial adenylate cyclases, and formate hydrogen lyase transcription activator FhlA) domain that uses a covalently attached linear tetrapyrrole (bilin) chromophore to sense light. Knotted red/far-red phytochromes are widespread in both bacteria and eukaryotes, but cyanobacteria also contain knotless red/far-red phytochromes and cyanobacteriochromes (CBCRs). Unlike typical phytochromes, CBCRs require only the GAF domain for bilin binding, chromophore ligation, and full, reversible photoconversion. CBCRs can sense a wide range of wavelengths (ca. 330-750 nm) and can regulate phototaxis, second messenger metabolism, and optimization of the cyanobacterial light-harvesting apparatus. However, the origins of CBCRs are not well understood: we do not know when or why CBCRs evolved, or what selective advantages led to retention of early CBCRs in cyanobacterial genomes. In the current work, we use the increasing availability of genomes and metagenome-assembled-genomes from early-branching cyanobacteria to explore the origins of CBCRs. We reaffirm the earliest branches in CBCR evolution. We also show that early-branching cyanobacteria contain late-branching CBCRs, implicating early appearance of CBCRs during cyanobacterial evolution. Moreover, we show that early-branching CBCRs behave as integrators of light and pH, providing a potential unique function for early CBCRs that led to their retention and subsequent diversification. Our results thus provide new insight into the origins of these diverse cyanobacterial photoreceptors.
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Affiliation(s)
- Nathan C Rockwell
- 31 Briggs Hall, Department of Molecular and Cell Biology, One Shields Avenue, University of California at Davis, Davis, CA 95616, USA.
| | - J Clark Lagarias
- 31 Briggs Hall, Department of Molecular and Cell Biology, One Shields Avenue, University of California at Davis, Davis, CA 95616, USA.
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2
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Gisriel CJ, Shen G, Brudvig GW, Bryant DA. Structure of the antenna complex expressed during far-red light photoacclimation in Synechococcus sp. PCC 7335. J Biol Chem 2024; 300:105590. [PMID: 38141759 PMCID: PMC10810746 DOI: 10.1016/j.jbc.2023.105590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 11/28/2023] [Accepted: 12/12/2023] [Indexed: 12/25/2023] Open
Abstract
Far-red light photoacclimation, or FaRLiP, is a facultative response exhibited by some cyanobacteria that allows them to absorb and utilize lower energy light (700-800 nm) than the wavelengths typically used for oxygenic photosynthesis (400-700 nm). During this process, three essential components of the photosynthetic apparatus are altered: photosystem I, photosystem II, and the phycobilisome. In all three cases, at least some of the chromophores found in these pigment-protein complexes are replaced by chromophores that have red-shifted absorbance relative to the analogous complexes produced in visible light. Recent structural and spectroscopic studies have elucidated important features of the two photosystems when altered to absorb and utilize far-red light, but much less is understood about the modified phycobiliproteins made during FaRLiP. We used single-particle, cryo-EM to determine the molecular structure of a phycobiliprotein core complex comprising allophycocyanin variants that absorb far-red light during FaRLiP in the marine cyanobacterium Synechococcus sp. PCC 7335. The structure reveals the arrangement of the numerous red-shifted allophycocyanin variants and the probable locations of the chromophores that serve as the terminal emitters in this complex. It also suggests how energy is transferred to the photosystem II complexes produced during FaRLiP. The structure additionally allows comparisons with other previously studied allophycocyanins to gain insights into how phycocyanobilin chromophores can be tuned to absorb far-red light. These studies provide new insights into how far-red light is harvested and utilized during FaRLiP, a widespread cyanobacterial photoacclimation mechanism.
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Affiliation(s)
| | - Gaozhong Shen
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA.
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3
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Šunderić M, Gligorijević N, Milčić M, Minić S, Nedić O, Nikolić M. Phycocyanobilin is a new binding partner of human alpha-2-macroglobulin that protects the protein against oxidative stress. J Biomol Struct Dyn 2023:1-11. [PMID: 37592733 DOI: 10.1080/07391102.2023.2248273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
Under simulated physiological conditions, this study investigates the interaction between nutraceutical phycocyanobilin (PCB) and the universal anti-protease protein human alpha-2-macroglobulin (α2M). Extensive molecular docking analyses on multiple α2M conformations, spectroscopic techniques, and α2M activity assays were utilized to examine the complex formation. The results revealed that for every protein conformation, two high energy binding sites exist: the first, conformationally independent, at the interface region between two monomer chains and the second, conformationally dependent, in the pocket composed of amino acids from four distinct domains (TED, RBD, CUB, and MG2) of the single protein chain. Spectrofluorimetric measurements indicated a moderate affinity between α2M and PCB with a moderately high binding constant of 6.3 × 105 M-1 at 25 °C. The binding of PCB to α2M resulted in minor changes in the secondary structure content of α2M. Furthermore, PCB protected α2M from oxidation and preserved its anti-protease activity in the oxidative environment. These findings suggest that PCB binding could indirectly impact the body's response to oxidative stress by influencing α2M's role in controlling enzyme activity during the inflammatory process.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Miloš Šunderić
- Department for Metabolism, Institute for the Application of Nuclear Energy, University of Belgrade, Belgrade/Zemun, Serbia
| | - Nikola Gligorijević
- Department of Chemistry, Institute of Chemistry, Technology, and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Miloš Milčić
- Department of General and Inorganic Chemistry, Faculty of Chemistry, University of Belgrade, Belgrade, Serbia
| | - Simeon Minić
- Department of Biochemistry and Center of Excellence for Molecular Food Sciences, Faculty of Chemistry, University of Belgrade, Belgrade, Serbia
| | - Olgica Nedić
- Department for Metabolism, Institute for the Application of Nuclear Energy, University of Belgrade, Belgrade/Zemun, Serbia
| | - Milan Nikolić
- Department of Biochemistry and Center of Excellence for Molecular Food Sciences, Faculty of Chemistry, University of Belgrade, Belgrade, Serbia
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4
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McCarty MF, Benzvi C, Vojdani A, Lerner A. Nutraceutical strategies for alleviation of UVB phototoxicity. Exp Dermatol 2023. [PMID: 36811352 DOI: 10.1111/exd.14777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 02/11/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023]
Abstract
Ultraviolet B exposure to keratinocytes promotes carcinogenesis by inducing pyrimidine dimer lesions in DNA, suppressing the nucleotide excision repair mechanism required to fix them, inhibiting the apoptosis required for the elimination of initiated cells, and driving cellular proliferation. Certain nutraceuticals - most prominently spirulina, soy isoflavones, long-chain omega-3 fatty acids, the green tea catechin epigallocatechin gallate (EGCG) and Polypodium leucotomos extract - have been shown to oppose photocarcinogenesis, as well as sunburn and photoaging, in UVB-exposed hairless mice. It is proposed that spirulina provides protection in this regard via phycocyanobilin-mediated inhibition of Nox1-dependent NADPH oxidase; that soy isoflavones do so by opposing NF-κB transcriptional activity via oestrogen receptor-beta; that the benefit of eicosapentaenoic acid reflects decreased production of prostaglandin E2; and that EGCG counters UVB-mediated phototoxicity via inhibition of the epidermal growth factor receptor. The prospects for practical nutraceutical down-regulation of photocarcinogenesis, sunburn, and photoaging appear favourable.
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Affiliation(s)
- Mark F McCarty
- Catalytic Longevity Foundation, San Diego, California, USA
| | - Carina Benzvi
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Tel Hashomer, Israel
| | | | - Aaron Lerner
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Tel Hashomer, Israel.,Ariel University, Ariel, Israel
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Joutsuka T, Nanasawa R, Igarashi K, Horie K, Sugishima M, Hagiwara Y, Wada K, Fukuyama K, Yano N, Mori S, Ostermann A, Kusaka K, Unno M. Neutron crystallography and quantum chemical analysis of bilin reductase PcyA mutants reveal substrate and catalytic residue protonation states. J Biol Chem 2022; 299:102763. [PMID: 36463961 PMCID: PMC9800206 DOI: 10.1016/j.jbc.2022.102763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 11/16/2022] [Accepted: 11/29/2022] [Indexed: 12/04/2022] Open
Abstract
PcyA, a ferredoxin-dependent bilin pigment reductase, catalyzes the site-specific reduction of the two vinyl groups of biliverdin (BV), producing phycocyanobilin. Previous neutron crystallography detected both the neutral BV and its protonated form (BVH+) in the wildtype (WT) PcyA-BV complex, and a nearby catalytic residue Asp105 was found to have two conformations (protonated and deprotonated). Semiempirical calculations have suggested that the protonation states of BV are reflected in the absorption spectrum of the WT PcyA-BV complex. In the previously determined absorption spectra of the PcyA D105N and I86D mutants, complexed with BV, a peak at 730 nm, observed in the WT, disappeared and increased, respectively. Here, we performed neutron crystallography and quantum chemical analysis of the D105N-BV and I86D-BV complexes to determine the protonation states of BV and the surrounding residues and study the correlation between the absorption spectra and protonation states around BV. Neutron structures elucidated that BV in the D105N mutant is in a neutral state, whereas that in the I86D mutant is dominantly in a protonated state. Glu76 and His88 showed different hydrogen bonding with surrounding residues compared with WT PcyA, further explaining why D105N and I86D have much lower activities for phycocyanobilin synthesis than the WT PcyA. Our quantum mechanics/molecular mechanics calculations of the absorption spectra showed that the spectral change in D105N arises from Glu76 deprotonation, consistent with the neutron structure. Collectively, our findings reveal more mechanistic details of bilin pigment biosynthesis.
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Affiliation(s)
- Tatsuya Joutsuka
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan,Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan,For correspondence: Tatsuya Joutsuka; Masaki Unno
| | - Ryota Nanasawa
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan
| | - Keisuke Igarashi
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan
| | - Kazuki Horie
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan
| | - Masakazu Sugishima
- Department of Medical Biochemistry, Kurume University School of Medicine, Kurume, Fukuoka, Japan
| | - Yoshinori Hagiwara
- Department of Biochemistry and Applied Chemistry, National Institute of Technology, Kurume College, Kurume, Fukuoka, Japan
| | - Kei Wada
- Department of Medical Sciences, University of Miyazaki, Miyazaki, Miyazaki, Japan
| | - Keiichi Fukuyama
- Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan
| | - Naomine Yano
- Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan
| | - Seiji Mori
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan,Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan
| | - Andreas Ostermann
- Heinz Maier-Leibnitz Zentrum (MLZ), Technical University Munich, Garching, Germany
| | - Katsuhiro Kusaka
- Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan
| | - Masaki Unno
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan,Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan,For correspondence: Tatsuya Joutsuka; Masaki Unno
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6
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Alhefeiti M, Chandra F, Gupta RK, Saleh N. Dyeing Non-Recyclable Polyethylene Plastic with Photoacid Phycocyanobilin from Spirulina Algae: Ultrafast Photoluminescence Studies. Polymers (Basel) 2022; 14:polym14224811. [PMID: 36432938 PMCID: PMC9693856 DOI: 10.3390/polym14224811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/16/2022] [Accepted: 10/20/2022] [Indexed: 11/12/2022] Open
Abstract
Despite the enormous environmental damage caused by plastic waste, it makes up over one-third of globally produced plastics. Polyethylene (PE) wastes have low recycling but high production rates. Towards the construction of ionic solar cells from PE, the present work describes the loading of a bioactive photoacid phycocyanobilin (PCB) dye from the pigment of Spirulina blue-green algae (as a natural resource) on low-density polyethylene (LDPE) plastic film. Dyeing was confirmed by X-ray photoelectron spectroscopy (XPS). Upon excitation of the Soret-band (400 nm), the photoluminescence (PL) spectra of PCB in neat solvents revealed two prominent emission peaks at 450-550 and 600-700 nm. The first band assigned to bilirubin-like (PCBBR) species predominated the spectral profile in the highly rigid solvent glycerol and upon loading 0.45 % (w/w) of the dye on plastic. The photoluminescence excitation (PLE) spectra of PCB for the second region (Q-band) at 672 nm in the same solvents confirmed the ground state heterogenicity previously associated with the presence of PCBA (neutral), PCBB (cationic), and PCBC (anionic) conformers. Time-resolved photoluminescence (TRPL) measurements induced via excitation of all PCB species at 510 nm in methanol revealed three-lifetime components with τ1 = ~0.1 ns and τ2 = ~2 ns associated with PCBBR species and τ3 = ~5 ns pertinent to the long-living photoproduct X*. Decay-associated spectra (DAS) analysis of the photoluminescence transient spectra of the final dyed films in the solid-state confirmed the improved generation of the long-living photoproduct as manifested in a significant increase in the PL intensity (~100-fold) and lifetime value (~90 ns) in the Q-region upon loading 6.92 % (w/w) of the dye on plastic. The photoproduct species were presumably assigned to the deprotonated PCB species, suggesting improved ionic mobility. The potential implementation of the PCB-sensitized PE solid wastes for the fabrication of ionic solar cells is discussed.
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Affiliation(s)
- Maryam Alhefeiti
- Department of Chemistry, College of Science, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
| | - Falguni Chandra
- Department of Chemistry, College of Science, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
| | - Ravindra Kumar Gupta
- King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia
| | - Na’il Saleh
- Department of Chemistry, College of Science, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates
- Correspondence: ; Tel.: +971-(0)3-713-6138
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7
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Abstract
Phycocyanobilin (PCB) is a kind of light-harvesting pigment which naturally exists in algae and plays important roles in absorbing and transferring energy. Based on its antioxidant and optical properties, PCB has been applied in food, medicine, and cosmetics. Currently, PCB is mainly extracted from Spirulina through complicated steps; thus, the biosynthesis of PCB in Escherichia coli has attracted more attention. However, due to the lower catalytic efficiency of synthetic enzymes and the deficiency of precursors and cofactors, the titer of PCB remains at a low level. Here, we report the efficient synthesis of PCB by the expression of heme oxygenase-1 from Thermosynechococcus elongatus and PCB: ferredoxin oxidoreductase (PcyA) from Synechocystis sp. using a high-copy number plasmid with an inducible T7lac promoter and the assembly of these two enzymes at a suitable ratio of 2:1 with DNA scaffolds. Additionally, the synthesis of PCB was further enhanced by direct supplementation of 5-aminolevulinic acid (ALA), moderate overexpression of key enzymes in the heme biosynthetic pathway (hemB and hemH), and accelerated cycle of cofactors (NADPH) through the expression of NAD+ kinase and the addition of a reducing agent. Finally, based on the optimal conditions (Modified R medium with 200 mg/L ALA, 20 mg/L FeSO4·7H2O, and 5 g/L vitamin C induced by 0.8 mM isopropylthio-β-galactoside at 30 °C), the highest reported titer of PCB (28.32 mg/L) was obtained at the fermenter level by feeding glucose and FeSO4·7H2O. The strategies applied in this study will be useful for the synthesis of other natural pigments and PCB or heme derivatives in E. coli.
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Affiliation(s)
- Xinrui Zhao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Haixin Gao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Yuqi Wang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Ziwei Wang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
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8
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McCarty MF, Lerner A, DiNicolantonio JJ, Benzvi C. Nutraceutical Aid for Allergies - Strategies for Down-Regulating Mast Cell Degranulation. J Asthma Allergy 2021; 14:1257-1266. [PMID: 34737578 PMCID: PMC8558634 DOI: 10.2147/jaa.s332307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/24/2021] [Indexed: 11/23/2022] Open
Abstract
Interactions of antigens with the mast cell FcεRI-IgE receptor complex induce degranulation and boost synthesis of pro-inflammatory lipid mediators and cytokines. Activation of spleen tyrosine kinase (Syk) functions as a central hub in this signaling. The tyrosine phosphatase SHP-1 opposes Syk activity; stimulation of NADPH oxidase by FcεRI activation results in the production of oxidants that reversibly inhibit SHP-1, up-regulating the signal from Syk. Activated AMPK can suppress Syk activation by the FcεRI receptor, possibly reflecting its ability to phosphorylate the FcεRI beta subunit. Cyclic GMP, via protein kinase G II, enhances the activity of SHP-1 by phosphorylating its C-terminal region; this may explain its inhibitory impact on mast cell activation. Hydrogen sulfide (H2S) likewise opposes mast cell activation; H2S can boost AMPK activity, up-regulate cGMP production, and trigger Nrf2-mediated induction of Phase 2 enzymes - including heme oxygenase-1, whose generation of bilirubin suppresses NADPH oxidase activity. Phycocyanobilin (PCB), a chemical relative of bilirubin, shares its inhibitory impact on NADPH oxidase, rationalizing reported anti-allergic effects of PCB-rich spirulina ingestion. Phase 2 inducer nutraceuticals can likewise oppose the up-regulatory impact of NADPH oxidase on FcεRI signaling. AMPK can be activated with the nutraceutical berberine. High-dose biotin can boost cGMP levels in mast cells via direct stimulation of soluble guanylate cyclase. Endogenous generation of H2S in mast cells can be promoted by administering N-acetylcysteine and likely by taurine, which increases the expression of H2S-producing enzymes in the vascular system. Mast cell stabilization by benifuuki green tea catechins may reflect the decreased surface expression of FcεRI.
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Affiliation(s)
| | - Aaron Lerner
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Tel Hashomer, Israel
| | - James J DiNicolantonio
- Saint Luke's Mid America Heart Institute, Kansas City, MO, USA.,Advanced Ingredients for Dietary Products, AIDP, City of Industry, CA, USA
| | - Carina Benzvi
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Tel Hashomer, Israel
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Hu JH, Chang JW, Xu T, Wang J, Wang X, Lin R, Duanmu D, Liu L. Structural basis of bilin binding by the chlorophyll biosynthesis regulator GUN4. Protein Sci 2021; 30:2083-2091. [PMID: 34382282 DOI: 10.1002/pro.4164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 11/05/2022]
Abstract
The chlorophyll biosynthesis regulator GENOMES UNCOUPLED 4 (GUN4) is conserved in nearly all oxygenic photosynthetic organisms. Recently, GUN4 has been found to be able to bind the linear tetrapyrroles (bilins) and stimulate the magnesium chelatase activity in the unicellular green alga Chlamydomonas reinhardtii. Here, we characterize GUN4 proteins from Arabidopsis thaliana and the cyanobacterium Synechocystis sp. PCC 6803 for their ability to bind bilins, and present the crystal structures of Synechocystis GUN4 in biliverdin-bound, phycocyanobilin-bound, and phytochromobilin-bound forms at the resolutions of 1.05, 1.10, and 1.70 Å, respectively. These linear molecules adopt a cyclic-helical conformation, and bind more tightly than planar porphyrins to the tetrapyrrole-binding pocket of GUN4. Based on structural comparison, we propose a working model of GUN4 in regulation of tetrapyrrole biosynthetic pathway, and address the role of the bilin-bound GUN4 in retrograde signaling.
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Affiliation(s)
- Jiu-Hui Hu
- School of Life Sciences, Anhui University, Hefei, China
| | | | - Tao Xu
- School of Life Sciences, Anhui University, Hefei, China
| | - Jia Wang
- School of Life Sciences, Anhui University, Hefei, China.,Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Xiao Wang
- School of Life Sciences, Anhui University, Hefei, China.,Anhui Key Laboratory of Modern Biomanufacturing, Anhui University, Hefei, China
| | - Rongcheng Lin
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Deqiang Duanmu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Lin Liu
- School of Life Sciences, Anhui University, Hefei, China.,Anhui Key Laboratory of Modern Biomanufacturing, Anhui University, Hefei, China
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10
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Zhang W, Willows RD, Deng R, Li Z, Li M, Wang Y, Guo Y, Shi W, Fan Q, Martin SS, Rockwell NC, Lagarias JC, Duanmu D. Bilin-dependent regulation of chlorophyll biosynthesis by GUN4. Proc Natl Acad Sci U S A 2021; 118:e2104443118. [PMID: 33975960 DOI: 10.1073/pnas.2104443118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Biosyntheses of chlorophyll and heme in oxygenic phototrophs share a common trunk pathway that diverges with insertion of magnesium or iron into the last common intermediate, protoporphyrin IX. Since both tetrapyrroles are pro-oxidants, it is essential that their metabolism is tightly regulated. Here, we establish that heme-derived linear tetrapyrroles (bilins) function to stimulate the enzymatic activity of magnesium chelatase (MgCh) via their interaction with GENOMES UNCOUPLED 4 (GUN4) in the model green alga Chlamydomonas reinhardtii A key tetrapyrrole-binding component of MgCh found in all oxygenic photosynthetic species, CrGUN4, also stabilizes the bilin-dependent accumulation of protoporphyrin IX-binding CrCHLH1 subunit of MgCh in light-grown C. reinhardtii cells by preventing its photooxidative inactivation. Exogenous application of biliverdin IXα reverses the loss of CrCHLH1 in the bilin-deficient heme oxygenase (hmox1) mutant, but not in the gun4 mutant. We propose that these dual regulatory roles of GUN4:bilin complexes are responsible for the retention of bilin biosynthesis in all photosynthetic eukaryotes, which sustains chlorophyll biosynthesis in an illuminated oxic environment.
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11
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McCarty MF, DiNicolantonio JJ, Lerner A. A Fundamental Role for Oxidants and Intracellular Calcium Signals in Alzheimer's Pathogenesis-And How a Comprehensive Antioxidant Strategy May Aid Prevention of This Disorder. Int J Mol Sci 2021; 22:2140. [PMID: 33669995 PMCID: PMC7926325 DOI: 10.3390/ijms22042140] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/16/2021] [Accepted: 02/18/2021] [Indexed: 12/13/2022] Open
Abstract
Oxidative stress and increased cytoplasmic calcium are key mediators of the detrimental effects on neuronal function and survival in Alzheimer's disease (AD). Pathways whereby these perturbations arise, and then prevent dendritic spine formation, promote tau hyperphosphorylation, further amplify amyloid β generation, and induce neuronal apoptosis, are described. A comprehensive program of nutraceutical supplementation, comprised of the NADPH oxidase inhibitor phycocyanobilin, phase two inducers, the mitochondrial antioxidant astaxanthin, and the glutathione precursor N-acetylcysteine, may have important potential for antagonizing the toxic effects of amyloid β on neurons and thereby aiding prevention of AD. Moreover, nutraceutical antioxidant strategies may oppose the adverse impact of amyloid β oligomers on astrocyte clearance of glutamate, and on the ability of brain capillaries to export amyloid β monomers/oligomers from the brain. Antioxidants, docosahexaenoic acid (DHA), and vitamin D, have potential for suppressing microglial production of interleukin-1β, which potentiates the neurotoxicity of amyloid β. Epidemiology suggests that a health-promoting lifestyle, incorporating a prudent diet, regular vigorous exercise, and other feasible measures, can cut the high risk for AD among the elderly by up to 60%. Conceivably, complementing such lifestyle measures with long-term adherence to the sort of nutraceutical regimen outlined here may drive down risk for AD even further.
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Affiliation(s)
| | | | - Aaron Lerner
- Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, Tel Hashomer 5262000, Israel
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12
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Kikuchi H. Functional roles of the hexamer structure of C-phycocyanin revealed by calculation of absorption wavelength. FEBS Open Bio 2021; 11:164-172. [PMID: 33190413 PMCID: PMC7780113 DOI: 10.1002/2211-5463.13038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/27/2020] [Accepted: 11/11/2020] [Indexed: 11/11/2022] Open
Abstract
Cyanophyta-phycocyanin (C-PC) is the main constituent of the rod of phycobilisome (PBS), which is a highly ordered and large peripheral light-harvesting protein complex present on the cytoplasmic side of the thylakoid membrane in cyanobacteria and red algae. The C-PC monomer comprises two chains, α- and β-subunits, and aggregates to form ring-shaped trimers (αβ)3 with rotational symmetry. The ring-shaped trimer (αβ)3 is a structural block unit (SBU) that forms the rod of PBS. Two (αβ)3 SBUs are arranged in a face-to-face manner to form an (αβ)6 -hexamer. In this study, the electronic states of three phycocyanobilins, α84, β84, and β155 in C-phycocyanin, constituting the rod of the PBS, were calculated for both the trimer and hexamer models by considering the effect of the electrostatic field of protein moieties and water molecules. For the hexamer, the absorption wavelengths of α84, β84, and β155 were similar to those obtained experimentally; however, for the trimer, only the absorption wavelength of β155 shifted toward a shorter-wavelength. The nature of the hexamer structure as a hierarchical structure is revealed by considering the calculated absorption wavelength and energy transfer.
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Affiliation(s)
- Hiroto Kikuchi
- Department of PhysicsNippon Medical SchoolMusashinoJapan
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13
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McCarty MF, Iloki Assanga SB, Lewis Luján L, O’Keefe JH, DiNicolantonio JJ. Nutraceutical Strategies for Suppressing NLRP3 Inflammasome Activation: Pertinence to the Management of COVID-19 and Beyond. Nutrients 2020; 13:E47. [PMID: 33375692 PMCID: PMC7823562 DOI: 10.3390/nu13010047] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 12/09/2020] [Accepted: 12/16/2020] [Indexed: 02/03/2023] Open
Abstract
Inflammasomes are intracellular protein complexes that form in response to a variety of stress signals and that serve to catalyze the proteolytic conversion of pro-interleukin-1β and pro-interleukin-18 to active interleukin-1β and interleukin-18, central mediators of the inflammatory response; inflammasomes can also promote a type of cell death known as pyroptosis. The NLRP3 inflammasome has received the most study and plays an important pathogenic role in a vast range of pathologies associated with inflammation-including atherosclerosis, myocardial infarction, the complications of diabetes, neurological and autoimmune disorders, dry macular degeneration, gout, and the cytokine storm phase of COVID-19. A consideration of the molecular biology underlying inflammasome priming and activation enables the prediction that a range of nutraceuticals may have clinical potential for suppressing inflammasome activity-antioxidants including phycocyanobilin, phase 2 inducers, melatonin, and N-acetylcysteine, the AMPK activator berberine, glucosamine, zinc, and various nutraceuticals that support generation of hydrogen sulfide. Complex nutraceuticals or functional foods featuring a number of these agents may find utility in the prevention and control of a wide range of medical disorders.
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Affiliation(s)
| | - Simon Bernard Iloki Assanga
- Department of Research and Postgraduate in Food, University of Sonora, Centro 83000, Mexico; (S.B.I.A.); (L.L.L.)
| | - Lidianys Lewis Luján
- Department of Research and Postgraduate in Food, University of Sonora, Centro 83000, Mexico; (S.B.I.A.); (L.L.L.)
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14
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Jähnigen S, Sebastiani D. Carbon Atoms Speaking Out: How the Geometric Sensitivity of 13C Chemical Shifts Leads to Understanding the Colour Tuning of Phycocyanobilin in Cph1 and AnPixJ. Molecules 2020; 25:E5505. [PMID: 33255423 PMCID: PMC7727823 DOI: 10.3390/molecules25235505] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 11/29/2022] Open
Abstract
We present a combined quantum mechanics/molecular mechanics (QM/MM) molecular dynamics-statistical approach for the interpretation of nuclear magnetic resonance (NMR) chemical shift patterns in phycocyanobilin (PCB). These were originally associated with colour tuning upon photoproduct formation in red/green-absorbing cyanobacteriochrome AnPixJg2 and red/far-red-absorbing phytochrome Cph1Δ2. We pursue an indirect approach without computation of the absorption frequencies since the molecular geometry of cofactor and protein are not accurately known. Instead, we resort to a heuristic determination of the conjugation length in PCB through the experimental NMR chemical shift patterns, supported by quantum chemical calculations. We have found a characteristic correlation pattern of 13C chemical shifts to specific bond orders within the π-conjugated system, which rests on the relative position of carbon atoms with respect to electron-withdrawing groups and the polarisation of covalent bonds. We propose the inversion of this regioselective relationship using multivariate statistics and to apply it to the known experimental NMR chemical shifts in order to predict changes in the bond alternation pattern. Therefrom the extent of electronic conjugation, and eventually the change in absorption frequency, can be derived. In the process, the consultation of explicit mesomeric formulae plays an important role to qualitatively account for possible conjugation scenarios of the chromophore. While we are able to consistently associate the NMR chemical shifts with hypsochromic and bathochromic shifts in the Pg and Pfr, our approach represents an alternative method to increase the explanatory power of NMR spectroscopic data in proteins.
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Affiliation(s)
| | - Daniel Sebastiani
- Institut für Chemie, Naturwissenschaftliche Fakultät II, Martin-Luther-Universität Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany;
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15
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Wang F, Fang J, Guan K, Luo S, Dogra V, Li B, Ma D, Zhao X, Lee KP, Sun P, Xin J, Liu T, Xing W, Kim C. The Arabidopsis CRUMPLED LEAF protein, a homolog of the cyanobacterial bilin lyase, retains the bilin-binding pocket for a yet unknown function. Plant J 2020; 104:964-978. [PMID: 32860438 DOI: 10.1111/tpj.14974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 07/27/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
The photosynthetic bacterial phycobiliprotein lyases, also called CpcT lyases, catalyze the biogenesis of phycobilisome, a light-harvesting antenna complex, through the covalent attachment of chromophores to the antenna proteins. The Arabidopsis CRUMPLED LEAF (CRL) protein is a homolog of the cyanobacterial CpcT lyase. Loss of CRL leads to multiple lesions, including localized foliar cell death, constitutive expression of stress-related nuclear genes, abnormal cell cycle, and impaired plastid division. Notwithstanding the apparent phenotypes, the function of CRL still remains elusive. To gain insight into the function of CRL, we examined whether CRL still retains the capacity to bind with the bacterial chromophore phycocyanobilin (PCB) and its plant analog phytochromobilin (PΦB). The revealed structure of the CpcT domain of CRL is comparable to that of the CpcT lyase, despite the low sequence identity. The subsequent in vitro biochemical assays found, as shown for the CpcT lyase, that PCB/PΦB binds to the CRL dimer. However, some mutant forms of CRL, substantially compromised in their bilin-binding ability, still restore the crl-induced multiple lesions. These results suggest that although CRL retains the bilin-binding pocket, it seems not functionally associated with the crl-induced multiple lesions.
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Affiliation(s)
- Fangfang Wang
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Jun Fang
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Kaoling Guan
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Shengji Luo
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Vivek Dogra
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Bingqi Li
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Demin Ma
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Xinyan Zhao
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Keun Pyo Lee
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Pengkai Sun
- National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China
| | - Jian Xin
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Tong Liu
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Weiman Xing
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Chanhong Kim
- Shanghai Center for Plant Stress Biology and CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
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McCarty MF, Lerner A. Perspective: Prospects for Nutraceutical Support of Intestinal Barrier Function. Adv Nutr 2020; 12:316-324. [PMID: 33126251 PMCID: PMC8243597 DOI: 10.1093/advances/nmaa139] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/28/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022] Open
Abstract
Impairment of intestinal barrier function is linked to certain pathologies and to aging, and can be a cause of bacterial infections, systemic and hepatic inflammation, food allergies, and autoimmune disorders. The formation and maintenance of intestinal tight junctions is supported by glucagon-like peptide-2 (GLP-2), which via insulin-like growth factor I activity boosts phosphoinositide 3-kinase/Akt/mammalian target of rapamycin complex 1 (PI3K/Akt/mTORC1) signaling in enterocytes. 5'-AMP-activated protein kinase (AMPK) activity as well as estrogen receptor-β (ERβ) activity are also protective in this regard. Conversely, activation of mitogen-activated protein kinases (MAPKs) and cellular Src (c-Src) under inflammatory conditions can induce dissociation of tight junctions. Hence, nutraceuticals that promote GLP-2 secretion from L cells-effective pre/probiotics, glycine, and glutamine-as well as diets rich in soluble fiber or resistant starch, can support intestinal barrier function. AMPK activators-notably berberine and the butyric acid produced by health-promoting microflora-are also beneficial in this regard, as are soy isoflavones, which function as selective agonists for ERβ. The adverse impact of MAPK and c-Src overactivation on the intestinal barrier can be combatted with various antioxidant measures, including phycocyanobilin, phase 2-inducer nutraceuticals, and N-acetylcysteine. These considerations suggest that rationally designed functional foods or complex supplementation programs could have clinical potential for supporting and restoring healthful intestinal barrier function.
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Song JY, Lee HY, Yang HW, Song JJ, Lagarias JC, Park YI. Spectral and photochemical diversity of tandem cysteine cyanobacterial phytochromes. J Biol Chem 2020; 295:6754-6766. [PMID: 32184354 DOI: 10.1074/jbc.ra120.012950] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/13/2020] [Indexed: 11/06/2022] Open
Abstract
The atypical trichromatic cyanobacterial phytochrome NpTP1 from Nostoc punctiforme ATCC 29133 is a linear tetrapyrrole (bilin)-binding photoreceptor protein that possesses tandem-cysteine residues responsible for shifting its light-sensing maximum to the violet spectral region. Using bioinformatics and phylogenetic analyses, here we established that tandem-cysteine cyanobacterial phytochromes (TCCPs) compose a well-supported monophyletic phytochrome lineage distinct from prototypical red/far-red cyanobacterial phytochromes. To investigate the light-sensing diversity of this family, we compared the spectroscopic properties of NpTP1 (here renamed NpTCCP) with those of three phylogenetically diverged TCCPs identified in the draft genomes of Tolypothrix sp. PCC7910, Scytonema sp. PCC10023, and Gloeocapsa sp. PCC7513. Recombinant photosensory core modules of ToTCCP, ScTCCP, and GlTCCP exhibited violet-blue-absorbing dark-states consistent with dual thioether-linked phycocyanobilin (PCB) chromophores. Photoexcitation generated singly-linked photoproduct mixtures with variable ratios of yellow-orange and red-absorbing species. The photoproduct ratio was strongly influenced by pH and by mutagenesis of TCCP- and phytochrome-specific signature residues. Our experiments support the conclusion that both photoproduct species possess protonated 15E bilin chromophores, but differ in the ionization state of the noncanonical "second" cysteine sulfhydryl group. We found that the ionization state of this and other residues influences subsequent conformational change and downstream signal transmission. We also show that tandem-cysteine phytochromes present in eukaryotes possess similar amino acid substitutions within their chromophore-binding pocket, which tune their spectral properties in an analogous fashion. Taken together, our findings provide a roadmap for tailoring the wavelength specificity of plant phytochromes to optimize plant performance in diverse natural and artificial light environments.
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Affiliation(s)
- Ji-Young Song
- Department of Biological Sciences, Chungnam National University, Daejeon 34134, Korea
| | - Ha Yong Lee
- Department of Biological Sciences, Chungnam National University, Daejeon 34134, Korea
| | - Hee Wook Yang
- Department of Biological Sciences, Chungnam National University, Daejeon 34134, Korea
| | - Ji-Joon Song
- Department of Biological Science and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - J Clark Lagarias
- Department of Molecular and Cellular Biology, University of California Davis, Davis, California 95616
| | - Youn-Il Park
- Department of Biological Sciences, Chungnam National University, Daejeon 34134, Korea
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18
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Pavón-Fuentes N, Marín-Prida J, Llópiz-Arzuaga A, Falcón-Cama V, Campos-Mojena R, Cervantes-Llanos M, Piniella-Matamoros B, Pentón-Arias E, Pentón-Rol G. Phycocyanobilin reduces brain injury after endothelin-1- induced focal cerebral ischaemia. Clin Exp Pharmacol Physiol 2019; 47:383-392. [PMID: 31732975 DOI: 10.1111/1440-1681.13214] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 09/27/2019] [Accepted: 11/12/2019] [Indexed: 12/11/2022]
Abstract
Pharmacological therapies for interrupting biochemical events of the ischaemic cascade and protecting against stroke in humans are as yet unavailable. Up to now, the neuroprotective activity in cerebral ischaemia of phycocyanobilin (PCB), a tetrapyrrolic natural antioxidant, has not been fully examined. Here, we evaluated if PCB protects PC12 neuronal cells against oxygen and glucose deprivation plus reperfusion, and its protective effects in a rat model of endothelin-1-induced focal brain ischaemia. PCB was purified from the cyanobacteria Spirulina platensis and characterized by spectrophotometric, liquid and gas chromatography and mass spectrometry techniques. In Wistar rats, PCB at 50, 100 and 200 μg/kg or phosphate-buffered saline (vehicle) was administered intraperitoneally at equal subdoses in a therapeutic schedule (30 minutes, 1, 3 and 6 hours after the surgery). Brain expression of myelin basic protein (MBP) and the enzyme CNPase was determined by immunoelectron microscopy. PCB was obtained with high purity (>95%) and the absence of solvent contaminants and was able to ameliorate PC12 cell ischaemic injury. PCB treatment significantly decreased brain infarct volume, limited the exploratory behaviour impairment and preserved viable cortical neurons in ischaemic rats in a dose-dependent manner, compared to the vehicle group. Furthermore, PCB at high doses restored the MBP and CNPase expression levels in ischaemic rats. An improved PCB purification method from its natural source is reported, obtaining PCB that is suitable for pharmacological trials showing neuroprotective effects against experimental ischaemic stroke. Therefore, PCB could be a therapeutic pharmacological alternative for ischaemic stroke patients.
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Affiliation(s)
| | - Javier Marín-Prida
- Centre for Research and Biological Evaluations (CEIEB), Institute of Pharmacy and Food, University of Havana, Havana, Cuba
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19
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Stepanenko OV, Stepanenko OV, Shpironok OG, Fonin AV, Kuznetsova IM, Turoverov KK. Near-Infrared Markers based on Bacterial Phytochromes with Phycocyanobilin as a Chromophore. Int J Mol Sci 2019; 20:ijms20236067. [PMID: 31810174 PMCID: PMC6928796 DOI: 10.3390/ijms20236067] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 11/27/2019] [Accepted: 11/29/2019] [Indexed: 12/03/2022] Open
Abstract
Biomarkers engineered on the basis of bacterial phytochromes with biliverdin IXα (BV) cofactor as a chromophore are increasingly used in cell biology and biomedicine, since their absorption and fluorescence spectra lie within the so-called optical “transparency window” of biological tissues. However, the quantum yield of BV fluorescence in these biomarkers does not exceed 0.145. The task of generating biomarkers with a higher fluorescence quantum yield remains relevant. To address the problem, we proposed the use of phycocyanobilin (PCB) as a chromophore of biomarkers derived from bacterial phytochromes. In this work, we characterized the complexes of iRFP713 evolved from RpBphP2 and its mutant variants with different location of cysteine residues capable of covalent tetrapyrrole attachment with the PCB cofactor. All analyzed proteins assembled with PCB were shown to have a higher fluorescence quantum yield than the proteins assembled with BV. The iRFP713/V256C and iRFP713/C15S/V256C assembled with PCB have a particularly high quantum yield of 0.5 and 0.45, which exceeds the quantum yield of all currently available near-infrared biomarkers. Moreover, PCB has 4 times greater affinity for iRFP713/V256C and iRFP713/C15S/V256C proteins compared to BV. These data establish iRFP713/V256C and iRFP713/C15S/V256C assembled with the PCB chromophore as promising biomarkers for application in vivo. The analysis of the spectral properties of the tested biomarkers allowed for suggesting that the high-fluorescence quantum yield of the PCB chromophore can be attributed to the lower mobility of the D-ring of PCB compared to BV.
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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; (O.V.S.); (O.V.S.); (O.G.S.); (A.V.F.); (I.M.K.)
| | - 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; (O.V.S.); (O.V.S.); (O.G.S.); (A.V.F.); (I.M.K.)
| | - Olesya G. Shpironok
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky ave., St. Petersburg 194064, Russia; (O.V.S.); (O.V.S.); (O.G.S.); (A.V.F.); (I.M.K.)
| | - Alexander V. Fonin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky ave., St. Petersburg 194064, Russia; (O.V.S.); (O.V.S.); (O.G.S.); (A.V.F.); (I.M.K.)
| | - 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; (O.V.S.); (O.V.S.); (O.G.S.); (A.V.F.); (I.M.K.)
| | - 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; (O.V.S.); (O.V.S.); (O.G.S.); (A.V.F.); (I.M.K.)
- Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya str., 29, St. Petersburg 194064, Russia
- Correspondence: ; Tel.: +7-812-297-19-57
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20
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McCarty MF, Iloki-Assanga S. Co-administration of Phycocyanobilin and/or Phase 2-Inducer Nutraceuticals for Prevention of Opiate Tolerance. Curr Pharm Des 2019; 24:2250-2254. [PMID: 30039753 DOI: 10.2174/1381612824666180723162730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/08/2018] [Accepted: 07/17/2018] [Indexed: 11/22/2022]
Abstract
Chronic use of opiates for control of chronic pain is complicated by the development of tolerance and hyperalgesia, and hence usually entails dose escalation and diminished efficacy. Our evolving understanding of the mechanisms mediating induction of morphine tolerance may enable discovery of adjunct measures which can prevent this tolerance; this essay proposes that certain nutraceuticals may have utility in this regard. Considerable evidence now points to an obligate role for production of peroxynitrite and other oxidants in the dorsal horn in development of morphine tolerance. Various isoforms of NADPH oxidase are the chief source of the superoxide which gives rise to these oxidants. Since heme oxygenase, via its products bilirubin and carbon monoxide, functions as a physiological inhibitor of various isoforms of NADPH oxidase, phase 2-inducing nutraceuticals with blood brain-barrier permeability such as lipoic acid, an effective inducer of heme oxygenase-1, may have potential for prevention of morphine tolerance; indeed, this has been demonstrated in a mouse study. The phycocyanobilin (PhyCB) chromophore of spirulina, a structural analog of biliverdin, shares bilirubin's ability to inhibit NAPDH oxidase complexes; hence, administration of spirulina or of PhyCB-enriched spirulina extracts merits evaluation in rodent models of morphine tolerance. Uric acid quenches peroxynitrite-derived radicals, and its plasma level can be boosting via supplementation with inosine; indeed, administration of inosine has been shown to counteract development of hyperalgesia in rodents. If practical doses of these agents can be shown to prevent morphine tolerance and hyperalgesia in rodents, their use as adjuvants to clinical opiate therapy should be assessed.
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Affiliation(s)
- Mark F McCarty
- Catalytic Longevity, 811 B Nahant Ct., San Diego, CA 92109, United States
| | - Simon Iloki-Assanga
- Departamento de Ciencias Quimico Biologicas, Universidad de Sonora, Hermosillo, Mexico
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21
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DiNicolantonio JJ, McCarty MF, O’Keefe JH. Antioxidant bilirubin works in multiple ways to reduce risk for obesity and its health complications. Open Heart 2018; 5:e000914. [PMID: 30364545 PMCID: PMC6196942 DOI: 10.1136/openhrt-2018-000914] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/26/2018] [Indexed: 12/30/2022] Open
Affiliation(s)
- James J DiNicolantonio
- Department of Preventive Cardiology, Saint Luke’s Mid America Heart Institute, Kansas City, Missouri, USA
| | | | - James H O’Keefe
- Department of Preventive Cardiology, Saint Luke’s Mid America Heart Institute, Kansas City, Missouri, USA
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22
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He Q, Tang QY, Sun YF, Zhou M, Gärtner W, Zhao KH. Chromophorylation of cyanobacteriochrome Slr1393 from Synechocystis sp. PCC 6803 is regulated by protein Slr2111 through allosteric interaction. J Biol Chem 2018; 293:17705-17715. [PMID: 30242127 DOI: 10.1074/jbc.ra118.003830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 08/13/2018] [Indexed: 11/06/2022] Open
Abstract
Cyanobacteriochromes (CBCRs) are photochromic proteins in cyanobacteria that act as photosensors. CBCRs bind bilins as chromophores and sense nearly the entire visible spectrum of light, but the regulation of the chromophorylation of CBCRs is unknown. Slr1393 from Synechocystis sp. PCC 6803 is a CBCR containing three consecutive GAF (cGMP phosphodiesterase, adenylyl cyclase, and FhlA protein) domains, of which only the third one (Slr1393g3) can be phycocyanobilin-chromophorylated. The protein Slr2111 from Synechocystis sp. PCC 6803 includes a cystathionine β-synthase (CBS) domain pair of an as yet unknown function at its N terminus. CBS domains are often characterized as sensors of cellular energy status by binding nucleotides. In this work, we demonstrate that Slr2111 strongly interacts with Slr1393 in vivo and in vitro, which generates a complex in a 1:1 molar ratio. This tight interaction inhibits the chromophorylation of Slr1393g3, even if the chromophore is present. Instead, the complex stability and thereby the chromophorylation of Slr1393 are regulated by the binding of nucleotides (ATP, ADP, AMP) to the CBS domains of Slr2111 with varying affinities. It is demonstrated that residues Asp-53 and Arg-97 of Slr2111 are involved in nucleotide binding. While ATP binds to Slr2111, the association between the two proteins gets weaker and chromophorylation of Slr1393 are enabled. In contrast, AMP binding to Slr2111 leads to a stronger association, thereby inhibiting the chromophorylation. It is concluded that Slr2111 acts as a sensor of the cellular energy status that regulates the chromophorylation of Slr1393 and thereby its function as a light-driven histidine kinase.
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Affiliation(s)
- Qi He
- From the State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Qi-Ying Tang
- From the State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Ya-Fang Sun
- From the State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Ming Zhou
- From the State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Wolfgang Gärtner
- Institute for Analytical Chemistry, University of Leipzig, 04103 Leipzig, Germany
| | - Kai-Hong Zhao
- From the State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China.
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23
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Kyriakakis P, Catanho M, Hoffner N, Thavarajah W, Hu VJ, Chao SS, Hsu A, Pham V, Naghavian L, Dozier LE, Patrick GN, Coleman TP. Biosynthesis of Orthogonal Molecules Using Ferredoxin and Ferredoxin-NADP + Reductase Systems Enables Genetically Encoded PhyB Optogenetics. ACS Synth Biol 2018; 7:706-717. [PMID: 29301067 PMCID: PMC5820651 DOI: 10.1021/acssynbio.7b00413] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transplanting metabolic reactions from one species into another has many uses as a research tool with applications ranging from optogenetics to crop production. Ferredoxin (Fd), the enzyme that most often supplies electrons to these reactions, is often overlooked when transplanting enzymes from one species to another because most cells already contain endogenous Fd. However, we have shown that the production of chromophores used in Phytochrome B (PhyB) optogenetics is greatly enhanced in mammalian cells by expressing bacterial and plant Fds with ferredoxin-NADP+ reductases (FNR). We delineated the rate limiting factors and found that the main metabolic precursor, heme, was not the primary limiting factor for producing either the cyanobacterial or plant chromophores, phycocyanobilin or phytochromobilin, respectively. In fact, Fd is limiting, followed by Fd+FNR and finally heme. Using these findings, we optimized the PCB production system and combined it with a tissue penetrating red/far-red sensing PhyB optogenetic gene switch in animal cells. We further characterized this system in several mammalian cell lines using red and far-red light. Importantly, we found that the light-switchable gene system remains active for several hours upon illumination, even with a short light pulse, and requires very small amounts of light for maximal activation. Boosting chromophore production by matching metabolic pathways with specific ferredoxin systems will enable the unparalleled use of the many PhyB optogenetic tools and has broader implications for optimizing synthetic metabolic pathways.
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Affiliation(s)
- Phillip Kyriakakis
- Department
of Bioengineering, University of California, San Diego, 9500 Gilman
Drive, La Jolla, California 92093-0412, United States
| | - Marianne Catanho
- Department
of Bioengineering, University of California, San Diego, 9500 Gilman
Drive, La Jolla, California 92093-0412, United States
| | - Nicole Hoffner
- Neurosciences
Graduate Program, University of California, San Diego, 9500 Gilman
Drive, La Jolla, California 92093-0412, United States
| | - Walter Thavarajah
- Department
of Bioengineering, University of California, San Diego, 9500 Gilman
Drive, La Jolla, California 92093-0412, United States
| | - Vincent J. Hu
- Department
of Bioengineering, University of California, San Diego, 9500 Gilman
Drive, La Jolla, California 92093-0412, United States
| | - Syh-Shiuan Chao
- Frank
H. Better School of Medicine, Quinnipiac University, 370 Bassett Road, North Haven, Connecticut 06473, United States
| | - Athena Hsu
- School
of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0412, United States
| | - Vivian Pham
- Roy J. and
Lucille A. Carver College of Medicine, University of Iowa, 451 Newton Road, Iowa City, Iowa 52242, United States
| | - Ladan Naghavian
- Department
of Bioengineering, University of California, San Diego, 9500 Gilman
Drive, La Jolla, California 92093-0412, United States
| | - Lara E. Dozier
- Section
of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093-0347, United States
| | - Gentry N. Patrick
- Section
of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093-0347, United States
| | - Todd P. Coleman
- Department
of Bioengineering, University of California, San Diego, 9500 Gilman
Drive, La Jolla, California 92093-0412, United States
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24
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McCarty MF. Supplementation with Phycocyanobilin, Citrulline, Taurine, and Supranutritional Doses of Folic Acid and Biotin-Potential for Preventing or Slowing the Progression of Diabetic Complications. Healthcare (Basel) 2017; 5:E15. [PMID: 28335416 PMCID: PMC5371921 DOI: 10.3390/healthcare5010015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/23/2017] [Accepted: 03/06/2017] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress, the resulting uncoupling of endothelial nitric oxide synthase (eNOS), and loss of nitric oxide (NO) bioactivity, are key mediators of the vascular and microvascular complications of diabetes. Much of this oxidative stress arises from up-regulated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. Phycocyanobilin (PhyCB), the light-harvesting chromophore in edible cyanobacteria such as spirulina, is a biliverdin derivative that shares the ability of free bilirubin to inhibit certain isoforms of NADPH oxidase. Epidemiological studies reveal that diabetics with relatively elevated serum bilirubin are less likely to develop coronary disease or microvascular complications; this may reflect the ability of bilirubin to ward off these complications via inhibition of NADPH oxidase. Oral PhyCB may likewise have potential in this regard, and has been shown to protect diabetic mice from glomerulosclerosis. With respect to oxidant-mediated uncoupling of eNOS, high-dose folate can help to reverse this by modulating the oxidation status of the eNOS cofactor tetrahydrobiopterin (BH4). Oxidation of BH4 yields dihydrobiopterin (BH2), which competes with BH4 for binding to eNOS and promotes its uncoupling. The reduced intracellular metabolites of folate have versatile oxidant-scavenging activity that can prevent oxidation of BH4; concurrently, these metabolites promote induction of dihydrofolate reductase, which functions to reconvert BH2 to BH4, and hence alleviate the uncoupling of eNOS. The arginine metabolite asymmetric dimethylarginine (ADMA), typically elevated in diabetics, also uncouples eNOS by competitively inhibiting binding of arginine to eNOS; this effect is exacerbated by the increased expression of arginase that accompanies diabetes. These effects can be countered via supplementation with citrulline, which efficiently enhances tissue levels of arginine. With respect to the loss of NO bioactivity that contributes to diabetic complications, high dose biotin has the potential to "pinch hit" for diminished NO by direct activation of soluble guanylate cyclase (sGC). High-dose biotin also may aid glycemic control via modulatory effects on enzyme induction in hepatocytes and pancreatic beta cells. Taurine, which suppresses diabetic complications in rodents, has the potential to reverse the inactivating impact of oxidative stress on sGC by boosting synthesis of hydrogen sulfide. Hence, it is proposed that concurrent administration of PhyCB, citrulline, taurine, and supranutritional doses of folate and biotin may have considerable potential for prevention and control of diabetic complications. Such a regimen could also be complemented with antioxidants such as lipoic acid, N-acetylcysteine, and melatonin-that boost cellular expression of antioxidant enzymes and glutathione-as well as astaxanthin, zinc, and glycine. The development of appropriate functional foods might make it feasible for patients to use complex nutraceutical regimens of the sort suggested here.
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Affiliation(s)
- Mark F McCarty
- Catalytic Longevity, 7831 Rush Rose Dr., Apt. 316, Carlsbad, CA 92009, USA.
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25
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Scoglio S, Lo Curcio V, Catalani S, Palma F, Battistelli S, Benedetti S. Inhibitory effects of Aphanizomenon flos-aquae constituents on human UDP-glucose dehydrogenase activity. J Enzyme Inhib Med Chem 2016; 31:1492-7. [PMID: 26903444 DOI: 10.3109/14756366.2016.1149478] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVE The purpose of this study was to investigate the in vitro inhibitory effects of the edible microalga Aphanizomenon flos-aquae (AFA) on human UDP-α-d-glucose 6-dehydrogenase (UGDH) activity, a cytosolic enzyme involved both in tumor progression and in phytochemical bioavailability. METHODS Both the hydrophilic and ethanolic AFA extracts as well as the constitutive active principles phycocyanin (PC), phycocyanobilin (PCB) and mycosporine-like amino acids (MAAs) were tested. RESULTS Among AFA components, PCB presented the strongest inhibitory effect on UGDH activity, acting as a competitive inhibitor with respect to UDP-glucose and a non-competitive inhibitor with respect to NAD(+). In preliminary experiments, AFA PCB was also effective in reducing the colony formation capacity of PC-3 prostate cancer cells and FTC-133 thyroid cancer cells. CONCLUSIONS Overall, these findings confirmed that AFA and its active principles are natural compounds with high biological activity. Further studies evaluating the effects of AFA PCB in reducing tumor cell growth and phytochemical glucuronidation are encouraged.
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Affiliation(s)
| | - Valeria Lo Curcio
- b Department of Biomolecular Sciences , University of Urbino "Carlo Bo" , Urbino , Italy
| | - Simona Catalani
- b Department of Biomolecular Sciences , University of Urbino "Carlo Bo" , Urbino , Italy
| | - Francesco Palma
- b Department of Biomolecular Sciences , University of Urbino "Carlo Bo" , Urbino , Italy
| | - Serafina Battistelli
- b Department of Biomolecular Sciences , University of Urbino "Carlo Bo" , Urbino , Italy
| | - Serena Benedetti
- b Department of Biomolecular Sciences , University of Urbino "Carlo Bo" , Urbino , Italy
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26
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Song C, Lang C, Kopycki J, Hughes J, Matysik J. NMR chemical shift pattern changed by ammonium sulfate precipitation in cyanobacterial phytochrome Cph1. Front Mol Biosci 2015; 2:42. [PMID: 26284254 PMCID: PMC4516977 DOI: 10.3389/fmolb.2015.00042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 07/06/2015] [Indexed: 11/25/2022] Open
Abstract
Phytochromes are dimeric biliprotein photoreceptors exhibiting characteristic red/far-red photocycles. Full-length cyanobacterial phytochrome Cph1 from Synechocystis 6803 is soluble initially but tends to aggregate in a concentration-dependent manner, hampering attempts to solve the structure using NMR and crystallization methods. Otherwise, the Cph1 sensory module (Cph1Δ2), photochemically indistinguishable from the native protein and used extensively in structural and other studies, can be purified to homogeneity in >10 mg amounts at mM concentrations quite easily. Bulk precipitation of full-length Cph1 by ammonium sulfate (AmS) was expected to allow us to produce samples for solid-state magic-angle spinning (MAS) NMR from dilute solutions before significant aggregation began. It was not clear, however, what effects the process of partial dehydration might have on the molecular structure. Here we test this by running solid-state MAS NMR experiments on AmS-precipitated Cph1Δ2 in its red-absorbing Pr state carrying uniformly 13C/15N-labeled phycocyanobilin (PCB) chromophore. 2D 13C–13C correlation experiments allowed a complete assignment of 13C responses of the chromophore. Upon precipitation, 13C chemical shifts for most of PCB carbons move upfield, in which we found major changes for C4 and C6 atoms associated with the A-ring positioning. Further, the broad spectral lines seen in the AmS 13C spectrum reflect primarily the extensive inhomogeneous broadening presumably due to an increase in the distribution of conformational states in the protein, in which less free water is available to partake in the hydration shells. Our data suggest that the effect of dehydration process indeed leads to changes of electronic structure of the bilin chromophore and a decrease in its mobility within the binding pocket, but not restricted to the protein surface. The extent of the changes induced differs from the freezing process of the solution samples routinely used in previous MAS NMR and crystallographic studies. AmS precipitation might nevertheless provide useful protein structure/functional information for full-length Cph1 in cases where neither X-ray crystallography nor conventional NMR methods are available.
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Affiliation(s)
- Chen Song
- Leids Instituut voor Chemisch Onderzoek, Universiteit Leiden Leiden, Netherlands ; Institut für Analytische Chemie, Fakultät für Chemie and Mineralogie, Universität Leipzig Leipzig, Germany
| | - Christina Lang
- Institut für Pflanzenphysiologie, Justus-Liebig-Universität Gießen Gießen, Germany
| | - Jakub Kopycki
- Institut für Pflanzenphysiologie, Justus-Liebig-Universität Gießen Gießen, Germany
| | - Jon Hughes
- Institut für Pflanzenphysiologie, Justus-Liebig-Universität Gießen Gießen, Germany
| | - Jörg Matysik
- Leids Instituut voor Chemisch Onderzoek, Universiteit Leiden Leiden, Netherlands ; Institut für Analytische Chemie, Fakultät für Chemie and Mineralogie, Universität Leipzig Leipzig, Germany
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27
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Xu XL, Gutt A, Mechelke J, Raffelberg S, Tang K, Miao D, Valle L, Borsarelli CD, Zhao KH, Gärtner W. Combined mutagenesis and kinetics characterization of the bilin-binding GAF domain of the protein Slr1393 from the Cyanobacterium Synechocystis PCC6803. Chembiochem 2014; 15:1190-9. [PMID: 24764310 DOI: 10.1002/cbic.201400053] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Indexed: 01/11/2023]
Abstract
The gene slr1393 from Synechocystis sp. PCC6803 encodes a protein composed of three GAF domains, a PAS domain, and a histidine kinase domain. GAF3 is the sole domain able to bind phycocyanobilin (PCB) as chromophore and to accomplish photochemistry: switching between a red-absorbing parental and a green-absorbing photoproduct state (λmax =649 and 536 nm, respectively). Conversions in both directions were followed by time-resolved absorption spectroscopy with the separately expressed GAF3 domain of Slr1393. Global fit analysis of the recorded absorbance changes yielded three lifetimes (3.2 μs, 390 μs, and 1.5 ms) for the red-to-green conversion, and 1.2 μs, 340 μs, and 1 ms for the green-to-red conversion. In addition to the wild-type (WT) protein, 24 mutated proteins were studied spectroscopically. The design of these site-directed mutations was based on sequence alignments with related proteins and by employing the crystal structure of AnPixJg2 (PDB ID: 3W2Z), a Slr1393 orthologous from Anabaena sp. PCC7120. The structure of AnPixJg2 was also used as template for model building, thus confirming the strong structural similarity between the proteins, and for identifying amino acids to target for mutagenesis. Only amino acids in close proximity to the chromophore were exchanged, as these were considered likely to have an impact on the spectral and dynamic properties. Three groups of mutants were found: some showed absorption features similar to the WT protein, a second group showed modified absorbance properties, and the third group had lost the ability to bind the chromophore. The most unexpected result was obtained for the exchange at residue 532 (N532Y). In vivo assembly yielded a red-absorbing, WT-like protein. Irradiation, however, not only converted it into the green-absorbing form, but also produced a 660 nm, further-red-shifted absorbance band. This photoproduct was fully reversible to the parental form upon green light irradiation.
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Affiliation(s)
- Xiu-Ling Xu
- Max-Planck-Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim (Germany)
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28
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Marín-Prida J, Pavón-Fuentes N, Llópiz-Arzuaga A, Fernández-Massó JR, Delgado-Roche L, Mendoza-Marí Y, Santana SP, Cruz-Ramírez A, Valenzuela-Silva C, Nazábal-Gálvez M, Cintado-Benítez A, Pardo-Andreu GL, Polentarutti N, Riva F, Pentón-Arias E, Pentón-Rol G. Phycocyanobilin promotes PC12 cell survival and modulates immune and inflammatory genes and oxidative stress markers in acute cerebral hypoperfusion in rats. Toxicol Appl Pharmacol 2013; 272:49-60. [PMID: 23732081 DOI: 10.1016/j.taap.2013.05.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 05/17/2013] [Accepted: 05/21/2013] [Indexed: 01/23/2023]
Abstract
Since the inflammatory response and oxidative stress are involved in the stroke cascade, we evaluated here the effects of Phycocyanobilin (PCB, the C-Phycocyanin linked tetrapyrrole) on PC12 cell survival, the gene expression and the oxidative status of hypoperfused rat brain. After the permanent bilateral common carotid arteries occlusion (BCCAo), the animals were treated with saline or PCB, taking samples 24h post-surgery. Global gene expression was analyzed with GeneChip Rat Gene ST 1.1 from Affymetrix; the expression of particular genes was assessed by the Fast SYBR Green RT-PCR Master Mix and Bioplex methods; and redox markers (MDA, PP, CAT, SOD) were evaluated spectrophotometrically. The PCB treatment prevented the H2O2 and glutamate induced PC12 cell injury assessed by the MTT assay, and modulated 190 genes (93 up- and 97 down-regulated) associated to several immunological and inflammatory processes in BCCAo rats. Furthermore, PCB positively modulated 19 genes mostly related to a detrimental pro-inflammatory environment and counteracted the oxidative imbalance in the treated BCCAo animals. Our results support the view of an effective influence of PCB on major inflammatory mediators in acute cerebral hypoperfusion. These results suggest that PCB has a potential to be a treatment for ischemic stroke for which further studies are needed.
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Affiliation(s)
- Javier Marín-Prida
- Centre for Research and Biological Evaluations (CEIEB), Institute of Pharmacy and Food, University of Havana, Ave. 23 e/ 214 y 222, La Lisa, PO Box: 430, Havana, Cuba
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Röben M, Schmieder P. Assignment of phycocyanobilin in HMPT using triple resonance experiments. Magn Reson Chem 2011; 49:543-548. [PMID: 21815209 DOI: 10.1002/mrc.2776] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 05/11/2011] [Accepted: 05/12/2011] [Indexed: 05/31/2023]
Abstract
A complete assignment of all resonances of a small organic molecule is a prerequisite for a structure determination using NMR spectroscopy. This is conventionally obtained using a well-established strategy based on COSY, HMQC and HMBC spectra. In case of phycocyanobilin (PCB) in HMPT this strategy was unsuccessful due to the symmetry of the molecule and extreme signal overlap. Since (13)C and (15)N labeled material was available, an alternative strategy for resonance assignment was used. Triple resonance experiments derived from experiments conventionally performed for proteins are sensitive and easy to analyze. Their application led to a complete and unambiguous assignment using three types of experiments.
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Affiliation(s)
- Marco Röben
- Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125 Berlin, Germany
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