1
|
Liu Y, Harnden KA, Van Stappen C, Dikanov SA, Lu Y. A designed Copper Histidine-brace enzyme for oxidative depolymerization of polysaccharides as a model of lytic polysaccharide monooxygenase. Proc Natl Acad Sci U S A 2023; 120:e2308286120. [PMID: 37844252 PMCID: PMC10614608 DOI: 10.1073/pnas.2308286120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 09/03/2023] [Indexed: 10/18/2023] Open
Abstract
The "Histidine-brace" (His-brace) copper-binding site, composed of Cu(His)2 with a backbone amine, is found in metalloproteins with diverse functions. A primary example is lytic polysaccharide monooxygenase (LPMO), a class of enzymes that catalyze the oxidative depolymerization of polysaccharides, providing not only an energy source for native microorganisms but also a route to more effective industrial biomass conversion. Despite its importance, how the Cu His-brace site performs this unique and challenging oxidative depolymerization reaction remains to be understood. To answer this question, we have designed a biosynthetic model of LPMO by incorporating the Cu His-brace motif into azurin, an electron transfer protein. Spectroscopic studies, including ultraviolet-visible (UV-Vis) absorption and electron paramagnetic resonance, confirm copper binding at the designed His-brace site. Moreover, the designed protein is catalytically active towards both cellulose and starch, the native substrates of LPMO, generating degraded oligosaccharides with multiturnovers by C1 oxidation. It also performs oxidative cleavage of the model substrate 4-nitrophenyl-D-glucopyranoside, achieving a turnover number ~9% of that of a native LPMO assayed under identical conditions. This work presents a rationally designed artificial metalloenzyme that acts as a structural and functional mimic of LPMO, which provides a promising system for understanding the role of the Cu His-brace site in LPMO activity and potential application in polysaccharide degradation.
Collapse
Affiliation(s)
- Yiwei Liu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
- Department of Chemistry, University of Texas at Austin, Austin, TX78712
| | - Kevin A. Harnden
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Casey Van Stappen
- Department of Chemistry, University of Texas at Austin, Austin, TX78712
| | - Sergei A. Dikanov
- Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, Urbana, IL61801
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL61801
- Department of Chemistry, University of Texas at Austin, Austin, TX78712
| |
Collapse
|
2
|
González LJ, Bahr G, González MM, Bonomo RA, Vila AJ. In-cell kinetic stability is an essential trait in metallo-β-lactamase evolution. Nat Chem Biol 2023; 19:1116-1126. [PMID: 37188957 DOI: 10.1038/s41589-023-01319-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 03/21/2023] [Indexed: 05/17/2023]
Abstract
Protein stability is an essential property for biological function. In contrast to the vast knowledge on protein stability in vitro, little is known about the factors governing in-cell stability. Here we show that the metallo-β-lactamase (MBL) New Delhi MBL-1 (NDM-1) is a kinetically unstable protein on metal restriction that has evolved by acquiring different biochemical traits that optimize its in-cell stability. The nonmetalated (apo) NDM-1 is degraded by the periplasmic protease Prc that recognizes its partially unstructured C-terminal domain. Zn(II) binding renders the protein refractory to degradation by quenching the flexibility of this region. Membrane anchoring makes apo-NDM-1 less accessible to Prc and protects it from DegP, a cellular protease degrading misfolded, nonmetalated NDM-1 precursors. NDM variants accumulate substitutions at the C terminus that quench its flexibility, enhancing their kinetic stability and bypassing proteolysis. These observations link MBL-mediated resistance with the essential periplasmic metabolism, highlighting the importance of the cellular protein homeostasis.
Collapse
Affiliation(s)
- Lisandro J González
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina
- Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Guillermo Bahr
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina
- Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Mariano M González
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina
- Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Robert A Bonomo
- Research Service, Veterans Affairs Northeast Ohio Healthcare System, Cleveland, OH, USA
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Medical Service and GRECC, Veterans Affairs Northeast Ohio Healthcare System, Cleveland, OH, USA
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, OH, USA
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Department of Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina.
- Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, OH, USA.
| |
Collapse
|
3
|
Choi TS, Tezcan FA. Design of a Flexible, Zn-Selective Protein Scaffold that Displays Anti-Irving-Williams Behavior. J Am Chem Soc 2022; 144:18090-18100. [PMID: 36154053 PMCID: PMC9949983 DOI: 10.1021/jacs.2c08050] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Selective metal binding is a key requirement not only for the functions of natural metalloproteins but also for the potential applications of artificial metalloproteins in heterogeneous environments such as cells and environmental samples. The selection of transition-metal ions through protein design can, in principle, be achieved through the appropriate choice and the precise positioning of amino acids that comprise the primary metal coordination sphere. However, this task is made difficult by the intrinsic flexibility of proteins and the fact that protein design approaches generally lack the sub-Å precision required for the steric selection of metal ions. We recently introduced a flexible/probabilistic protein design strategy (MASCoT) that allows metal ions to search for optimal coordination geometry within a flexible, yet covalently constrained dimer interface. In an earlier proof-of-principle study, we used MASCoT to generate an artificial metalloprotein dimer, (AB)2, which selectively bound CoII and NiII over CuII (as well as other first-row transition-metal ions) through the imposition of a rigid octahedral coordination geometry, thus countering the Irving-Williams trend. In this study, we set out to redesign (AB)2 to examine the applicability of MASCoT to the selective binding of other metal ions. We report here the design and characterization of a new flexible protein dimer, B2, which displays ZnII selectivity over all other tested metal ions including CuII both in vitro and in cellulo. Selective, anti-Irving-Williams ZnII binding by B2 is achieved through the formation of a unique trinuclear Zn coordination motif in which His and Glu residues are rigidly placed in a tetrahedral geometry. These results highlight the utility of protein flexibility in the design and discovery of selective binding motifs.
Collapse
|
4
|
Guo J, Fisher OS. Orchestrating copper binding: structure and variations on the cupredoxin fold. J Biol Inorg Chem 2022; 27:529-540. [PMID: 35994119 DOI: 10.1007/s00775-022-01955-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/07/2022] [Indexed: 11/26/2022]
Abstract
A large number of copper binding proteins coordinate metal ions using a shared three-dimensional fold called the cupredoxin domain. This domain was originally identified in Type 1 "blue copper" centers but has since proven to be a common domain architecture within an increasingly large and diverse group of copper binding domains. The cupredoxin fold has a number of qualities that make it ideal for coordinating Cu ions for purposes including electron transfer, enzyme catalysis, assembly of other copper sites, and copper sequestration. The structural core does not undergo major conformational changes upon metal binding, but variations within the coordination environment of the metal site confer a range of Cu-binding affinities, reduction potentials, and spectroscopic properties. Here, we discuss these proteins from a structural perspective, examining how variations within the overall cupredoxin fold and metal binding sites are linked to distinct spectroscopic properties and biological functions. Expanding far beyond the blue copper proteins, cupredoxin domains are used by a growing number of proteins and enzymes as a means of binding copper ions, with many more likely remaining to be identified.
Collapse
Affiliation(s)
- Jing Guo
- Department of Chemistry, Lehigh University, Bethlehem, PA, USA
| | - Oriana S Fisher
- Department of Chemistry, Lehigh University, Bethlehem, PA, USA.
| |
Collapse
|
5
|
Rajbongshi J, Das DK, Mazumdar S. Spectroscopic and electrochemical studies of the pH-Induced transition in the CuA centre from Thermus thermophilus. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2021.120749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
6
|
Fedoretz-Maxwell BP, Shin CH, MacNeil GA, Worrall LJ, Park R, Strynadka NCJ, Walsby CJ, Warren JJ. The Impact of Second Coordination Sphere Methionine-Aromatic Interactions in Copper Proteins. Inorg Chem 2022; 61:5563-5571. [DOI: 10.1021/acs.inorgchem.2c00030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brooklyn P. Fedoretz-Maxwell
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Catherine H. Shin
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Gregory A. MacNeil
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Liam J. Worrall
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Rachel Park
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Natalie C. J. Strynadka
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Charles J. Walsby
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Jeffrey J. Warren
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| |
Collapse
|
7
|
Gibbs CA, Fedoretz-Maxwell BP, Warren JJ. On the roles of methionine and the importance of its microenvironments in redox metalloproteins. Dalton Trans 2022; 51:4976-4985. [PMID: 35253809 DOI: 10.1039/d1dt04387k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The amino acid residue methionine (Met) is commonly thought of as a ligand in redox metalloproteins, for example in cytochromes c and in blue copper proteins. However, the roles of Met can go beyond a simple ligand. The thioether functional group of Met allows it to be considered as a hydrophobic residue as well as one that is capable of weak dipolar interactions. In addition, the lone pairs on sulphur allow Met to interact with other groups, inluding the aforementioned metal ions. Because of its properties, Met can play diverse roles in metal coordination, fine tuning of redox reactions, or supporting protein structures. These roles are strongly influenced by the nature of the surrounding medium. Herein, we describe several common interactions between Met and surrounding aromatic amino acids and how they affect the physical properties of both copper and iron metalloproteins. While the importance of interactions between Met and other groups is established in biological systems, less is known about their roles in redox metalloproteins and our view is that this is an area that is ready for greater attention.
Collapse
Affiliation(s)
- Curtis A Gibbs
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
| | | | - Jeffrey J Warren
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
| |
Collapse
|
8
|
Chen X, Chen M, Wolynes PG, Wittung-Stafshede P, Gray HB. Frustration Dynamics and Electron-Transfer Reorganization Energies in Wild-Type and Mutant Azurins. J Am Chem Soc 2022; 144:4178-4185. [PMID: 35171591 PMCID: PMC8915257 DOI: 10.1021/jacs.1c13454] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
Long-range electron
tunneling through metalloproteins is facilitated
by evolutionary tuning of donor–acceptor electronic couplings,
formal electrochemical potentials, and active-site reorganization
energies. Although the minimal frustration of the folding landscape
enables this tuning, residual frustration in the vicinity of the metallocofactor
can allow conformational fluctuations required for protein function.
We show here that the constrained copper site in wild-type azurin
is governed by an intricate pattern of minimally frustrated local
and distant interactions that together enable rapid electron flow
to and from the protein. In contrast, sluggish electron transfer reactions
(unfavorable reorganization energies) of active-site azurin variants
are attributable to increased frustration near to as well as distant
from the copper site, along with an exaggerated oxidation-state dependence
of both minimally and highly frustrated interaction patterns.
Collapse
Affiliation(s)
- Xun Chen
- Center for Theoretical Biological Physics, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Mingchen Chen
- Center for Theoretical Biological Physics, Houston, Texas 77005, United States
| | - Peter G Wolynes
- Center for Theoretical Biological Physics, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, Houston, Texas 77005, United States.,Department of Biosciences, Rice University, Houston, Texas 77005, United States
| | - Pernilla Wittung-Stafshede
- Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Harry B Gray
- Beckman Institute and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| |
Collapse
|
9
|
Banerjee S, Chanakira MN, Hall J, Kerkan A, Dasgupta S, Martin DW. A review on bacterial redox dependent iron transporters and their evolutionary relationship. J Inorg Biochem 2022; 229:111721. [PMID: 35033753 DOI: 10.1016/j.jinorgbio.2022.111721] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 01/04/2022] [Accepted: 01/06/2022] [Indexed: 02/05/2023]
Abstract
Iron is an essential yet toxic micronutrient and its transport across biological membranes is tightly regulated in all living organisms. One such iron transporter, the Ftr-type permeases, is found in both eukaryotic and prokaryotic cells. These Ftr-type transporters are required for iron transport, predicted to form α-helical transmembrane structures, and conserve two ArgGluxxGlu (x = any amino acid) motifs. In the yeast Ftr transporter (Ftr1p), a ferroxidase (Fet3p) is required for iron transport in an oxidation coupled transport step. None of the bacterial Ftr-type transporters (EfeU and FetM from E. coli; cFtr from Campylobacter jejuni; FtrC from Brucella, Bordetella, and Burkholderia spp.) contain a ferroxidase protein. Bioinformatics report predicted periplasmic EfeO and FtrB (from the EfeUOB and FtrABCD systems) as novel cupredoxins. The Cu2+ binding and the ferrous oxidation properties of these proteins are uncharacterized and the other two bacterial Ftr-systems are expressed without any ferroxidase/cupredoxin, leading to controversy about the mode of function of these transporters. Here, we review published data on Ftr-type transporters to gain insight into their functional diversity. Based on original bioinformatics data presented here evolutionary relations between these systems are presented.
Collapse
Affiliation(s)
- Sambuddha Banerjee
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA.
| | - Mina N Chanakira
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
| | - Jonathan Hall
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
| | - Alexa Kerkan
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
| | - Saumya Dasgupta
- Department of Chemistry, Amity Institute of Applied Sciences, Amity University Kolkata, WB 700135, India
| | - Daniel W Martin
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| |
Collapse
|
10
|
Zhang Y, Dai Z, Zhang S, Yang X. The catalytic properties of Thermus thermophilus SG0.5JP17-16 laccase were regulated by the conformational dynamics of pocket loop 6. Biochim Biophys Acta Gen Subj 2021; 1865:129872. [PMID: 33588000 DOI: 10.1016/j.bbagen.2021.129872] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/07/2021] [Accepted: 02/08/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Laccase is one member of the blue multicopper oxidase family. It can catalyze the oxidation of various substrates. The Thermus thermophilus SG0.5JP17-16 laccase (lacTT) is thermostable, pH-stable, and high tolerance to halides, and can decolorize the synthetic dyes. In lacTT, the function of the loop 6 constructing the substrate-binding pocket wasn't clear. METHODS The residues Asp394 and Asp396 located in loop 6, and were used to probe how the loop 6 influenced catalytic properties of the laccase. Site-directed mutagenesis was performed for two amino acids. Kinetic assay was utilized to characterize the catalytic efficiency of mutants. Mutants with different catalytic activities were used to decolorize the synthetic dyes to clarify the relationship between the catalytic efficiency and dye decolorization. Redox potential, structural and spectral analyses were performed to explain the differences in laccase activity between wild type and mutant enzymes. RESULTS D394M, D394E and D394R mutants with the lower laccase activity displayed a decreased decolorization efficiency, while D396A, D396M and D396E mutant enzymes with higher catalytic efficiency decolorized the synthetic dye more efficiently than the wild type enzyme. CONCLUSIONS The pocket loop 6 might experience a conformational dynamics. The D394 residue controlled this conformation change by amino acid interaction networks containing the D396 residue at the entrance of substrate channel. GENERAL SIGNIFICANCES These studies may provide clues to improve the activity of the laccase for the better use in industrial applications, and/or contribute to further understanding the mechanism of laccase oxidation on the substrate.
Collapse
Affiliation(s)
- Yi Zhang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, People's Republic of China
| | - Zhuojun Dai
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, People's Republic of China
| | - Shumin Zhang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, People's Republic of China
| | - Xiaorong Yang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, People's Republic of China.
| |
Collapse
|
11
|
Harty ML, Sharma AN, Bearne SL. Catalytic properties of the metal ion variants of mandelate racemase reveal alterations in the apparent electrophilicity of the metal cofactor. Metallomics 2020; 11:707-723. [PMID: 30843025 DOI: 10.1039/c8mt00330k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mandalate racemase (MR) from Pseudomonas putida requires a divalent metal cation, usually Mg2+, to catalyse the interconversion of the enantiomers of mandelate. Although the active site Mg2+ may be replaced by Mn2+, Co2+, or Ni2+, substitution by these metal ions does not markedly (<10-fold) alter the kinetic parameters Kappm, kappcat, and (kcat/Km)app for the substrates (R)- and (S)-mandelate, and the alternative substrate (S)-trifluorolactate. Viscosity variation experiments with Mn2+-MR showed that the metal ion plays a role in the uniform binding of the transition states for enzyme-substrate association, the chemical step, and enzyme-product dissociation. Surprisingly, the competitive inhibition constants (Ki) for inhibition of each metalloenzyme variant by benzohydroxamate did not vary significantly with the identity of the metal ion unlike the marked variation of the stability constants (K1) observed for M2+·BzH complex formation in solution. A similar trend was observed for the inhibition of the metalloenzyme variants by F-, except for Mg2+-MR, which bound F- tighter than would be predicted based on the stability constants for formation of M2+·F- complexes in solution. Thus, the enzyme modifies the enatic state of the bound metal ion cofactor so that the apparent electrophilicity of Mg2+ is enhanced, while that of Ni2+ is attenuated, resulting in a levelling effect relative to the trends observed for the free metals in solution.
Collapse
Affiliation(s)
- Matthew L Harty
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
| | | | | |
Collapse
|
12
|
Zitare UA, Szuster J, Santalla MC, Morgada MN, Vila AJ, Murgida DH. Dynamical effects in metalloprotein heterogeneous electron transfer. Electrochim Acta 2020. [DOI: 10.1016/j.electacta.2020.136095] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
13
|
Zhu Y, Zhan J, Zhang Y, Lin Y, Yang X. The K428 residue from Thermus thermophilus SG0.5JP17-16 laccase plays the substantial role in substrate binding and oxidation. J Biomol Struct Dyn 2020; 39:1312-1320. [DOI: 10.1080/07391102.2020.1729864] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yanyun Zhu
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, People’s Republic Of China
| | - Jiangbo Zhan
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, People’s Republic Of China
| | - Yi Zhang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, People’s Republic Of China
| | - Ying Lin
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, People’s Republic Of China
| | - Xiaorong Yang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, People’s Republic Of China
| |
Collapse
|
14
|
Llases ME, Lisa MN, Morgada MN, Giannini E, Alzari PM, Vila AJ. Arabidopsis thaliana Hcc1 is a Sco-like metallochaperone for Cu A assembly in Cytochrome c Oxidase. FEBS J 2019; 287:749-762. [PMID: 31348612 DOI: 10.1111/febs.15016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/03/2019] [Accepted: 07/22/2019] [Indexed: 01/13/2023]
Abstract
The assembly of the CuA site in Cytochrome c Oxidase (COX) is a critical step for aerobic respiration in COX-dependent organisms. Several gene products have been associated with the assembly of this copper site, the most conserved of them belonging to the Sco family of proteins, which have been shown to perform different roles in different organisms. Plants express two orthologs of Sco proteins: Hcc1 and Hcc2. Hcc1 is known to be essential for plant development and for COX maturation, but its precise function has not been addressed until now. Here, we report the biochemical, structural and functional characterization of Arabidopsis thaliana Hcc1 protein (here renamed Sco1). We solved the crystal structure of the Cu+1 -bound soluble domain of this protein, revealing a tri coordinated environment involving a CxxxCxn H motif. We show that AtSco1 is able to work as a copper metallochaperone, inserting two Cu+1 ions into the CuA site in a model of CoxII. We also show that AtSco1 does not act as a thiol-disulfide oxido-reductase. Overall, this information sheds new light on the biochemistry of Sco proteins, highlighting the diversity of functions among them despite their high structural similarities. DATABASE: PDB entry 6N5U (Crystal structure of Arabidopsis thaliana ScoI with copper bound).
Collapse
Affiliation(s)
- María-Eugenia Llases
- Instituto de Biología Molecular y Celular de Rosario (IBR CONICET-UNR), Rosario, Argentina
| | - María-Natalia Lisa
- Instituto de Biología Molecular y Celular de Rosario (IBR CONICET-UNR), Rosario, Argentina.,Plataforma de Biología Estructural y Metabolómica (PLABEM), Rosario, Argentina
| | - Marcos N Morgada
- Instituto de Biología Molecular y Celular de Rosario (IBR CONICET-UNR), Rosario, Argentina.,Area Biofísica, Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Argentina
| | - Estefanía Giannini
- Instituto de Biología Molecular y Celular de Rosario (IBR CONICET-UNR), Rosario, Argentina
| | - Pedro M Alzari
- Unité de Microbiologie Structurale, Institut Pasteur, Université Paris Diderot, Paris, France
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR CONICET-UNR), Rosario, Argentina.,Plataforma de Biología Estructural y Metabolómica (PLABEM), Rosario, Argentina.,Area Biofísica, Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Argentina
| |
Collapse
|
15
|
Biochemistry of Copper Site Assembly in Heme-Copper Oxidases: A Theme with Variations. Int J Mol Sci 2019; 20:ijms20153830. [PMID: 31387303 PMCID: PMC6696091 DOI: 10.3390/ijms20153830] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 01/18/2023] Open
Abstract
Copper is an essential cofactor for aerobic respiration, since it is required as a redox cofactor in Cytochrome c Oxidase (COX). This ancient and highly conserved enzymatic complex from the family of heme-copper oxidase possesses two copper sites: CuA and CuB. Biosynthesis of the oxidase is a complex, stepwise process that requires a high number of assembly factors. In this review, we summarize the state-of-the-art in the assembly of COX, with special emphasis in the assembly of copper sites. Assembly of the CuA site is better understood, being at the same time highly variable among organisms. We also discuss the current challenges that prevent the full comprehension of the mechanisms of assembly and the pending issues in the field.
Collapse
|
16
|
Zitare UA, Szuster J, Santalla MC, Llases ME, Morgada MN, Vila AJ, Murgida DH. Fine Tuning of Functional Features of the Cu A Site by Loop-Directed Mutagenesis. Inorg Chem 2019; 58:2149-2157. [PMID: 30644741 DOI: 10.1021/acs.inorgchem.8b03244] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Here we report the spectroscopic and electrochemical characterization of three novel chimeric CuA proteins in which either one or the three loops surrounding the metal ions in the Thermus thermophilus protein have been replaced by homologous human and plant sequences while preserving the set of coordinating amino acids. These conservative modifications mimic basic differences between CuA sites from different organisms and allow for fine tuning the energy gap between alternative electronic ground states of CuA.. This results in a systematic modulation of thermodynamic and kinetic electron transfer (ET) parameters and in the selection of one of two possible redox-active molecular orbitals, which differ in the ET reorganization energy by a factor of 2. Moreover, the ET mechanism is found to be frictionally controlled, and the modifications introduced into the different chimeras do not affect the frictional activation parameter.
Collapse
Affiliation(s)
- Ulises A Zitare
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE) , Universidad de Buenos Aires and CONICET, 1428 Buenos Aires , Argentina
| | - Jonathan Szuster
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE) , Universidad de Buenos Aires and CONICET, 1428 Buenos Aires , Argentina
| | - María C Santalla
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE) , Universidad de Buenos Aires and CONICET, 1428 Buenos Aires , Argentina
| | - María E Llases
- Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Instituto de Biología Molecular y Celular de Rosario (IBR) , Universidad Nacional de Rosario and CONICET, 2000 Rosario , Argentina
| | - Marcos N Morgada
- Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Instituto de Biología Molecular y Celular de Rosario (IBR) , Universidad Nacional de Rosario and CONICET, 2000 Rosario , Argentina
| | - Alejandro J Vila
- Departamento de Química Biológica, Facultad de Ciencias Bioquímicas y Farmacéuticas , Instituto de Biología Molecular y Celular de Rosario (IBR) , Universidad Nacional de Rosario and CONICET, 2000 Rosario , Argentina
| | - Daniel H Murgida
- Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales , Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE) , Universidad de Buenos Aires and CONICET, 1428 Buenos Aires , Argentina
| |
Collapse
|
17
|
Abstract
Biological metal sites are optimized for function by conformational properties of the protein macroligand.
Collapse
Affiliation(s)
- Wilfred R. Hagen
- Delft University of Technology
- Department of Biotechnology
- 2629HZ Delft
- The Netherlands
| |
Collapse
|
18
|
The role of molecular crowding in long-range metalloprotein electron transfer: Dissection into site- and scaffold-specific contributions. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.10.069] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
19
|
Devlin T, Hofman CR, Acevedo ZPV, Kohler KR, Tao L, Britt RD, Hoke KR, Hunsicker-Wang LM. DEPC modification of the Cu A protein from Thermus thermophilus. J Biol Inorg Chem 2018; 24:117-135. [PMID: 30523412 DOI: 10.1007/s00775-018-1632-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 11/28/2018] [Indexed: 11/28/2022]
Abstract
The CuA center is the initial electron acceptor in cytochrome c oxidase, and it consists of two copper ions bridged by two cysteines and ligated by two histidines, a methionine, and a carbonyl in the peptide backbone of a nearby glutamine. The two ligating histidines are of particular interest as they may influence the electronic and redox properties of the metal center. To test for the presence of reactive ligating histidines, a portion of cytochrome c oxidase from the bacteria Thermus thermophilus that contains the CuA site (the TtCuA protein) was treated with the chemical modifier diethyl pyrocarbonate (DEPC) and the reaction followed through UV-visible, circular dichroism, and electron paramagnetic resonance spectroscopies at pH 5.0-9.0. A mutant protein (H40A/H117A) with the non-ligating histidines removed was similarly tested. Introduction of an electron-withdrawing DEPC-modification onto the ligating histidine 157 of TtCuA increased the reduction potential by over 70 mV, as assessed by cyclic voltammetry. Results from both proteins indicate that DEPC reacts with one of the two ligating histidines, modification of a ligating histidine raises the reduction potential of the CuA site, and formation of the DEPC adduct is reversible at room temperature. The existence of the reactive ligating histidine suggests that this residue may play a role in modulating the electronic and redox properties of TtCuA through kinetically-controlled proton exchange with the solvent. Lack of reactivity by the metalloproteins Sco and azurin, both of which contain a mononuclear copper center, indicate that reactivity toward DEPC is not a characteristic of all ligating histidines.
Collapse
Affiliation(s)
- Taylor Devlin
- Department of Chemistry, Trinity University, San Antonio, TX, 78212-7200, USA
- Department of Biophysics, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21218, USA
| | - Cristina R Hofman
- Department of Chemistry, Trinity University, San Antonio, TX, 78212-7200, USA
| | - Zachary P V Acevedo
- Department of Chemistry, Trinity University, San Antonio, TX, 78212-7200, USA
| | - Kelsey R Kohler
- Department of Chemistry, Trinity University, San Antonio, TX, 78212-7200, USA
| | - Lizhi Tao
- Department of Chemistry, University of California at Davis, Davis, CA, 95616, USA
| | - R David Britt
- Department of Chemistry, University of California at Davis, Davis, CA, 95616, USA
| | - Kevin R Hoke
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, GA, 30149, USA
| | | |
Collapse
|
20
|
Kayser B, Fereiro JA, Guo C, Cohen SR, Sheves M, Pecht I, Cahen D. Transistor configuration yields energy level control in protein-based junctions. NANOSCALE 2018; 10:21712-21720. [PMID: 30431054 DOI: 10.1039/c8nr06627b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The incorporation of proteins as functional components in electronic junctions has received much interest recently due to their diverse bio-chemical and physical properties. However, information regarding the energies of the frontier orbitals involved in their electron transport (ETp) has remained elusive. Here we employ a new method to quantitatively determine the energy position of the molecular orbital, nearest to the Fermi level (EF) of the electrode, in the electron transfer protein Azurin. The importance of the Cu(ii) redox center of Azurin is demonstrated by measuring gate-controlled conductance switching which is absent if Azurin's copper ions are removed. Comparing different electrode materials, a higher conductance and a lower gate-induced current onset is observed for the material with smaller work function, indicating that ETp via Azurin is LUMO-mediated. We use the difference in work function to calibrate the difference in gate-induced current onset for the two electrode materials, to a specific energy level shift and find that ETp via Azurin is near resonance. Our results provide a basis for mapping and studying the role of energy level positions in (bio)molecular junctions.
Collapse
Affiliation(s)
- Ben Kayser
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 76100, Israel.
| | | | | | | | | | | | | |
Collapse
|
21
|
Lopez LC, Mukhitov N, Handley LD, Hamme CS, Hofman CR, Euers L, McKinney JR, Piers AD, Wadler E, Hunsicker-Wang LM. Characterization and effect of metal ions on the formation of the Thermus thermophilus Sco mixed disulfide intermediate. Protein Sci 2018; 27:1942-1954. [PMID: 30168216 DOI: 10.1002/pro.3502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 11/09/2022]
Abstract
The Sco protein from Thermus thermophilus has previously been shown to perform a disulfide bond reduction in the CuA protein from T. thermophilus, which is a soluble protein engineered from subunit II of cytochrome ba 3 oxidase that lacks the transmembrane helix. The native cysteines on TtSco and TtCuA were mutated to serine residues to probe the reactivities of the individual cysteines. Conjugation of TNB to the remaining cysteine in TtCuA and subsequent release upon incubation with the complementary TtSco protein demonstrated the formation of the mixed disulfide intermediate. The cysteine of TtSco that attacks the disulfide bond in the target TtCuA protein was determined to be TtSco Cysteine 49. This cysteine is likely more reactive than Cysteine 53 due to a higher degree of solvent exposure. Removal of the metal binding histidine, His 139, does not change MDI formation. However, altering the arginine adjacent to the reactive cysteine in Sco (Arginine 48) does alter the formation of the MDI. Binding of Cu2+ or Cu+ to TtSco prior to reaction with TtCuA was found to preclude formation of the mixed disulfide intermediate. These results shed light on a mechanism of disulfide bond reduction by the TtSco protein and may point to a possible role of metal binding in regulating the activity. IMPORTANCE: The function of Sco is at the center of many studies. The disulfide bond reduction in CuA by Sco is investigated herein and the effect of metal ions on the ability to reduce and form a mixed disulfide intermediate are also probed.
Collapse
Affiliation(s)
- Liezelle C Lopez
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200.,Baylor School of Medicine, One Baylor Plaza, Houston, Texas, 77030
| | - Nikita Mukhitov
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139
| | - Lindsey D Handley
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200.,ThoughtSTEM, San Diego, California, 92108
| | - Cristina S Hamme
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200.,Lone Star Family Health Center, Conroe, Texas, 77034
| | - Cristina R Hofman
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200
| | - Lindsay Euers
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200.,Houston Methodist Hospital, Houston, Texas, 77303
| | - Jennifer R McKinney
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200.,Department of Maternal Fetal Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, Texas, 77004
| | - Amani D Piers
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200.,Department of Psychology, Drexel University, Philadelphia, Pennsylvania, 19104
| | - Ellen Wadler
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200.,University of Texas Health Science Center Houston School of Public Health, Houston, Texas, 77030
| | - Laura M Hunsicker-Wang
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas, 78212-7200
| |
Collapse
|
22
|
Espinoza-Cara A, Zitare U, Alvarez-Paggi D, Klinke S, Otero LH, Murgida DH, Vila AJ. Engineering a bifunctional copper site in the cupredoxin fold by loop-directed mutagenesis. Chem Sci 2018; 9:6692-6702. [PMID: 30310603 PMCID: PMC6115626 DOI: 10.1039/c8sc01444b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/27/2018] [Indexed: 12/30/2022] Open
Abstract
Copper sites in proteins are designed to perform either electron transfer or redox catalysis. Type 1 and CuA sites are electron transfer hubs bound to a rigid protein fold that prevents binding of exogenous ligands and side reactions. Here we report the engineering of two Type 1 sites by loop-directed mutagenesis within a CuA scaffold with unique electronic structures and functional features. A copper-thioether axial bond shorter than the copper-thiolate bond is responsible for the electronic structure features, in contrast to all other natural or chimeric sites where the copper thiolate bond is short. These sites display highly unusual features, such as: (1) a high reduction potential despite a strong interaction with the axial ligand, which we attribute to changes in the hydrogen bond network and (2) the ability to bind exogenous ligands such as imidazole and azide. This strategy widens the possibility of using natural protein scaffolds with functional features not present in nature.
Collapse
Affiliation(s)
- Andrés Espinoza-Cara
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) , Rosario , Argentina .
- Área Biofísica , Departamento de Química Biológica , Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario , Rosario , Argentina
| | - Ulises Zitare
- Departamento de Química Inorgánica , Analítica y Química Física-INQUIMAE , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires-CONICET , Buenos Aires , Argentina
| | - Damián Alvarez-Paggi
- Departamento de Química Inorgánica , Analítica y Química Física-INQUIMAE , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires-CONICET , Buenos Aires , Argentina
- Fundación Instituto Leloir , IIBBA-CONICET , Buenos Aires , Argentina
| | - Sebastián Klinke
- Fundación Instituto Leloir , IIBBA-CONICET , Buenos Aires , Argentina
- Plataforma Argentina de Biología Estructural y Metabolómica PLABEM. , Buenos Aires , Argentina
| | - Lisandro H Otero
- Fundación Instituto Leloir , IIBBA-CONICET , Buenos Aires , Argentina
- Plataforma Argentina de Biología Estructural y Metabolómica PLABEM. , Buenos Aires , Argentina
| | - Daniel H Murgida
- Departamento de Química Inorgánica , Analítica y Química Física-INQUIMAE , Facultad de Ciencias Exactas y Naturales , Universidad de Buenos Aires-CONICET , Buenos Aires , Argentina
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) , Rosario , Argentina .
- Área Biofísica , Departamento de Química Biológica , Facultad de Ciencias Bioquímicas y Farmacéuticas , Universidad Nacional de Rosario , Rosario , Argentina
- Plataforma Argentina de Biología Estructural y Metabolómica PLABEM. , Buenos Aires , Argentina
| |
Collapse
|
23
|
Maiti BK, Maia LB, Moro AJ, Lima JC, Cordas CM, Moura I, Moura JJG. Unusual Reduction Mechanism of Copper in Cysteine-Rich Environment. Inorg Chem 2018; 57:8078-8088. [PMID: 29956539 DOI: 10.1021/acs.inorgchem.8b00121] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Copper-cysteine interactions play an important role in Biology and herein we used the copper-substituted rubredoxin (Cu-Rd) from Desulfovibrio gigas to gain further insights into the copper-cysteine redox chemistry. EPR spectroscopy results are consistent with Cu-Rd harboring a CuII center in a sulfur-rich coordination, in a distorted tetrahedral structure ( g∥,⊥ = 2.183 and 2.032 and A∥,⊥ = 76.4 × 10-4 and 12 × 10-4 cm-1). In Cu-Rd, two oxidation states at Cu-center (CuII and CuI) are associated with Cys oxidation-reduction, alternating in the redox cycle, as pointed by electrochemical studies that suggest internal geometry rearrangements associated with the electron transfer processes. The midpoint potential of [CuI(S-Cys)2(Cys-S-S-Cys)]/[CuII(S-Cys)4] redox couple was found to be -0.15 V vs NHE showing a large separation of cathodic and anodic peaks potential (Δ Ep = 0.575 V). Interestingly, sulfur-rich CuII-Rd is highly stable under argon in dark conditions, which is thermodynamically unfavorable to Cu-thiol autoreduction. The reduction of copper and concomitant oxidation of Cys can both undergo two possible pathways: oxidative as well as photochemical. Under O2, CuII plays the role of the electron carrier from one Cys to O2 followed by internal geometry rearrangement at the Cu site, which facilitates reduction at Cu-center to yield CuI(S-Cys)2(Cys-S-S-Cys). Photoinduced (irradiated at λex = 280 nm) reduction of the CuII center is observed by UV-visible photolysis (above 300 nm all bands disappeared) and tryptophan fluorescence (∼335 nm peak enhanced) experiments. In both pathways, geometry reorganization plays an important role in copper reduction yielding an energetically compatible donor-acceptor system. This model system provides unusual stability and redox chemistry rather than the universal Cu-thiol auto redox chemistry in cysteine-rich copper complexes.
Collapse
Affiliation(s)
- Biplab K Maiti
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal
| | - Luisa B Maia
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal
| | - Artur J Moro
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal
| | - João C Lima
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal
| | - Cristina M Cordas
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal
| | - Isabel Moura
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal
| | - José J G Moura
- LAQV, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade Nova de Lisboa , 2829-516 Caparica , Portugal
| |
Collapse
|
24
|
|
25
|
Nóbrega CS, Pauleta SR. Interaction between Neisseria gonorrhoeae bacterial peroxidase and its electron donor, the lipid-modified azurin. FEBS Lett 2018; 592:1473-1483. [PMID: 29665008 DOI: 10.1002/1873-3468.13053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/04/2018] [Accepted: 04/06/2018] [Indexed: 11/05/2022]
Abstract
The Neisseria gonorrhoeae bacterial cytochrome c peroxidase plays a key role in detoxifying the cells from H2 O2 by reducing it to water using the lipid-modified azurin, LAz, a small type 1 copper protein, as electron donor. Here, the interaction between these two proteins was characterized by steady-state kinetics, two-dimensional NMR and molecular docking simulations. LAz is an efficient electron donor capable of activating this enzyme. This electron transfer complex is weak with a hydrophobic character, with LAz binding close to the electron transferring heme of the enzyme. The high catalytic rate (39 ± 0.03 s-1 ) is explained by the LAz pre-orientation, due to a positive dipole moment, and by the fast-dynamic ensemble of orientations, suggested by the small chemical shifts.
Collapse
Affiliation(s)
- Cláudia S Nóbrega
- Microbial Stress Lab, UCIBIO, REQUIMTE, Department of Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Sofia R Pauleta
- Microbial Stress Lab, UCIBIO, REQUIMTE, Department of Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| |
Collapse
|
26
|
Kroneck PMH. Walking the seven lines: binuclear copper A in cytochrome c oxidase and nitrous oxide reductase. J Biol Inorg Chem 2017; 23:27-39. [PMID: 29218634 DOI: 10.1007/s00775-017-1510-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 10/20/2017] [Indexed: 01/19/2023]
Abstract
The enzymes nitrous oxide reductase (N2OR) and cytochrome c oxidase (COX) are constituents of important biological processes. N2OR is the terminal reductase in a respiratory chain converting N2O to N2 in denitrifying bacteria; COX is the terminal oxidase of the aerobic respiratory chain of certain bacteria and eukaryotic organisms transforming O2 to H2O accompanied by proton pumping. Different spectroscopies including magnetic resonance techniques, were applied to show that N2OR has a mixed-valent Cys-bridged [Cu1.5+(CyS)2Cu1.5+] copper site, and that such a binuclear center, called CuA, does also exist in COX. A sequence motif shared between the CuA center of N2OR and the subunit II of COX raises the issue of a putative evolutionary relationship of the two enzymes. The suggestion of a binuclear CuA in COX, with one unpaired electron delocalized between two equivalent Cu nuclei, was difficult to accept originally, even though regarded as a clever solution to many experimental observations. This minireview in honor of Helmut Sigel traces several of the critical steps forward in understanding the nature of CuA in N2OR and COX, and discusses its unique electronic features to some extent including the contributions made by the development of methodology and the discovery of a novel multi-copper enzyme. Left: X-band (9.130 GHz) and C-band (4.530 GHz, 1st harmonic display of experimental spectrum) EPR spectra of bovine heart cytochrome c oxidase, recorded at 20K. Right: Ribbon presentation of the CuA domain in cytochrome c oxidase and nitrous oxide reductase.
Collapse
Affiliation(s)
- Peter M H Kroneck
- Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
| |
Collapse
|
27
|
Maiti BK, Almeida RM, Moura I, Moura JJ. Rubredoxins derivatives: Simple sulphur-rich coordination metal sites and its relevance for biology and chemistry. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
28
|
Timón-Gómez A, Nývltová E, Abriata LA, Vila AJ, Hosler J, Barrientos A. Mitochondrial cytochrome c oxidase biogenesis: Recent developments. Semin Cell Dev Biol 2017; 76:163-178. [PMID: 28870773 DOI: 10.1016/j.semcdb.2017.08.055] [Citation(s) in RCA: 187] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 08/18/2017] [Accepted: 08/25/2017] [Indexed: 12/21/2022]
Abstract
Mitochondrial cytochrome c oxidase (COX) is the primary site of cellular oxygen consumption and is essential for aerobic energy generation in the form of ATP. Human COX is a copper-heme A hetero-multimeric complex formed by 3 catalytic core subunits encoded in the mitochondrial DNA and 11 subunits encoded in the nuclear genome. Investigations over the last 50 years have progressively shed light into the sophistication surrounding COX biogenesis and the regulation of this process, disclosing multiple assembly factors, several redox-regulated processes leading to metal co-factor insertion, regulatory mechanisms to couple synthesis of COX subunits to COX assembly, and the incorporation of COX into respiratory supercomplexes. Here, we will critically summarize recent progress and controversies in several key aspects of COX biogenesis: linear versus modular assembly, the coupling of mitochondrial translation to COX assembly and COX assembly into respiratory supercomplexes.
Collapse
Affiliation(s)
- Alba Timón-Gómez
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Eva Nývltová
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Luciano A Abriata
- Laboratory for Biomolecular Modeling & Protein Purification and Structure Facility, École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics, Switzerland
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Ocampo y Esmeralda, S2002LRK Rosario, Argentina
| | - Jonathan Hosler
- Department of Biochemistry, The University of Mississippi Medical Center, Jackson, MS, United States
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States; Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, United States.
| |
Collapse
|
29
|
Soldatova AV, Tao L, Romano CA, Stich TA, Casey WH, Britt RD, Tebo BM, Spiro TG. Mn(II) Oxidation by the Multicopper Oxidase Complex Mnx: A Binuclear Activation Mechanism. J Am Chem Soc 2017; 139:11369-11380. [PMID: 28712284 DOI: 10.1021/jacs.7b02771] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The bacterial protein complex Mnx contains a multicopper oxidase (MCO) MnxG that, unusually, catalyzes the two-electron oxidation of Mn(II) to MnO2 biomineral, via a Mn(III) intermediate. Although Mn(III)/Mn(II) and Mn(IV)/Mn(III) reduction potentials are expected to be high, we find a low reduction potential, 0.38 V (vs Normal Hydrogen Electrode, pH 7.8), for the MnxG type 1 Cu2+, the electron acceptor. Indeed the type 1 Cu2+ is not reduced by Mn(II) in the absence of molecular oxygen, indicating that substrate oxidation requires an activation step. We have investigated the enzyme mechanism via electronic absorption spectroscopy, using chemometric analysis to separate enzyme-catalyzed MnO2 formation from MnO2 nanoparticle aging. The nanoparticle aging time course is characteristic of nucleation and particle growth; rates for these processes followed expected dependencies on Mn(II) concentration and temperature, but exhibited different pH optima. The enzymatic time course is sigmoidal, signaling an activation step, prior to turnover. The Mn(II) concentration and pH dependence of a preceding lag phase indicates weak Mn(II) binding. The activation step is enabled by a pKa > 8.6 deprotonation, which is assigned to Mn(II)-bound H2O; it induces a conformation change (consistent with a high activation energy, 106 kJ/mol) that increases Mn(II) affinity. Mnx activation is proposed to decrease the Mn(III/II) reduction potential below that of type 1 Cu(II/I) by formation of a hydroxide-bridged binuclear complex, Mn(II)(μ-OH)Mn(II), at the substrate site. Turnover is found to depend cooperatively on two Mn(II) and is enabled by a pKa 7.6 double deprotonation. It is proposed that turnover produces a Mn(III)(μ-OH)2Mn(III) intermediate that proceeds to the enzyme product, likely Mn(IV)(μ-O)2Mn(IV) or an oligomer, which subsequently nucleates MnO2 nanoparticles. We conclude that Mnx exploits manganese polynuclear chemistry in order to facilitate an otherwise difficult oxidation reaction, as well as biomineralization. The mechanism of the Mn(III/IV) conversion step is elucidated in an accompanying paper .
Collapse
Affiliation(s)
- Alexandra V Soldatova
- Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195, United States
| | | | - Christine A Romano
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University , Portland, Oregon 97239, United States
| | | | | | | | - Bradley M Tebo
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University , Portland, Oregon 97239, United States
| | - Thomas G Spiro
- Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195, United States
| |
Collapse
|
30
|
Yamaguchi T, Nihei Y, Sutherland DEK, Stillman MJ, Kohzuma T. Stabilization of protein structure through π-π interaction in the second coordination sphere of pseudoazurin. Protein Sci 2017; 26:1921-1931. [PMID: 28691165 DOI: 10.1002/pro.3226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/01/2017] [Accepted: 07/04/2017] [Indexed: 11/11/2022]
Abstract
Noncovalent, weak interactions in the second coordination sphere of the copper active site of Pseudoazurin (PAz) from Achromobacter cycloclastes were examined using a series of Met16X variants. In this study, the differences in protein stability due to the changes in the nature of the 16th amino acid (Met, Phe, Val, Ile) were investigated by electrospray ionization mass spectrometry (ESI-MS) and far-UV circular dichroism (CD) as a result of acid denaturation. The percentage of native states (folded holo forms) of Met16Phe variants was estimated to be 75% at pH 2.9 although the wild-type (WT), Met16Val and Met16Ile PAz, became completely unfolded. The high stability under acidic conditions is correlated with the result of the active site being stabilized by the aromatic substitution of the Met16 residue. The π-π interaction in the second coordination sphere makes a significant contribution to the stability of active site and the protein matrix.
Collapse
Affiliation(s)
- Takahide Yamaguchi
- Graduate School of Science and Engineering, Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki, 310-8512, Japan
| | - Yuko Nihei
- Graduate School of Science and Engineering, Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki, 310-8512, Japan
| | - Duncan E K Sutherland
- Department of Biology, The University of Western Ontario, London, Ontario, Canada.,Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
| | - Martin J Stillman
- Department of Biology, The University of Western Ontario, London, Ontario, Canada.,Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
| | - Takamitsu Kohzuma
- Graduate School of Science and Engineering, Institute of Quantum Beam Science, Ibaraki University, Mito, Ibaraki, 310-8512, Japan
| |
Collapse
|
31
|
Levy AR, Turgeman M, Gevorkyan-Aiapetov L, Ruthstein S. The structural flexibility of the human copper chaperone Atox1: Insights from combined pulsed EPR studies and computations. Protein Sci 2017; 26:1609-1618. [PMID: 28543811 DOI: 10.1002/pro.3197] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 05/15/2017] [Indexed: 01/20/2023]
Abstract
Metallochaperones are responsible for shuttling metal ions to target proteins. Thus, a metallochaperone's structure must be sufficiently flexible both to hold onto its ion while traversing the cytoplasm and to transfer the ion to or from a partner protein. Here, we sought to shed light on the structure of Atox1, a metallochaperone involved in the human copper regulation system. Atox1 shuttles copper ions from the main copper transporter, Ctr1, to the ATP7b transporter in the Golgi apparatus. Conventional biophysical tools such as X-ray or NMR cannot always target the various conformational states of metallochaperones, owing to a requirement for crystallography or low sensitivity and resolution. Electron paramagnetic resonance (EPR) spectroscopy has recently emerged as a powerful tool for resolving biological reactions and mechanisms in solution. When coupled with computational methods, EPR with site-directed spin labeling and nanoscale distance measurements can provide structural information on a protein or protein complex in solution. We use these methods to show that Atox1 can accommodate at least four different conformations in the apo state (unbound to copper), and two different conformations in the holo state (bound to copper). We also demonstrate that the structure of Atox1 in the holo form is more compact than in the apo form. Our data provide insight regarding the structural mechanisms through which Atox1 can fulfill its dual role of copper binding and transfer.
Collapse
Affiliation(s)
- Ariel R Levy
- The Department of Chemistry, Faculty of Exact Science, Bar Ilan University, Ramat-Gan, 5290002, Israel
| | - Meital Turgeman
- The Department of Chemistry, Faculty of Exact Science, Bar Ilan University, Ramat-Gan, 5290002, Israel
| | - Lada Gevorkyan-Aiapetov
- The Department of Chemistry, Faculty of Exact Science, Bar Ilan University, Ramat-Gan, 5290002, Israel
| | - Sharon Ruthstein
- The Department of Chemistry, Faculty of Exact Science, Bar Ilan University, Ramat-Gan, 5290002, Israel
| |
Collapse
|
32
|
Roger M, Sciara G, Biaso F, Lojou E, Wang X, Bauzan M, Giudici-Orticoni MT, Vila AJ, Ilbert M. Impact of copper ligand mutations on a cupredoxin with a green copper center. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:351-359. [DOI: 10.1016/j.bbabio.2017.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 02/10/2017] [Accepted: 02/14/2017] [Indexed: 11/26/2022]
|
33
|
Chen H, Su B, Zhang T, Huang A, Liu H, Yu Y, Wang J. Engineering the metal-binding loop at a type 1 copper center by circular permutation. RSC Adv 2017. [DOI: 10.1039/c7ra11512a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Circular permutation of the cupredoxin azurin creates a break on the metal binding loop, highlighting the loop's flexibility.
Collapse
Affiliation(s)
- Honghui Chen
- College of Biotechnology
- Tianjin University of Science and Technology
- Tianjin
- China
- Tianjin Institute of Industrial Biotechnology
| | - Binbin Su
- College of Biotechnology
- Tianjin University of Science and Technology
- Tianjin
- China
- Tianjin Institute of Industrial Biotechnology
| | - Tongtong Zhang
- Tianjin Institute of Industrial Biotechnology
- Chinese Academy of Sciences
- Tianjin
- China
| | - Aiping Huang
- Tianjin Institute of Industrial Biotechnology
- Chinese Academy of Sciences
- Tianjin
- China
| | - Haiping Liu
- Tianjin Institute of Industrial Biotechnology
- Chinese Academy of Sciences
- Tianjin
- China
| | - Yang Yu
- Tianjin Institute of Industrial Biotechnology
- Chinese Academy of Sciences
- Tianjin
- China
| | - Jiangyun Wang
- Laboratory of RNA Biology
- Institute of Biophysics
- Chinese Academy of Sciences
- Beijing
- China
| |
Collapse
|
34
|
Dutta Gupta D, Usharani D, Mazumdar S. Mono-nuclear copper complexes mimicking the intermediates for the binuclear copper center of the subunit II of cytochrome oxidase: a peptide based approach. Dalton Trans 2016; 45:17624-17632. [PMID: 27747364 DOI: 10.1039/c6dt02977a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three stable copper complexes of peptides derived from the copper ion binding loop of the subunit II of cytochrome c oxidase have been prepared and characterized by various spectroscopic techniques. These stable copper complexes of peptides were found to exhibit cysteine, histidine and/or methionine ligation, which has predominant σ-contribution in the Cys-Cu charge transfer. The copper(ii) peptide complexes showed type-2 EPR spectra, which is uncommon in copper-cysteinate complexes. UV-visible spectra, Raman and EPR results support a tetragonal structure of the coordination geometry around the copper ion. The copper complex of the 9-amino acid peptide suggested the formation of a 'red' copper center while the copper complexes of the 12- and 11-amino acid peptides showed the formation of a 'green' copper center. The results provide insights on the first stable models of the copper complexes formed in the peptide scaffold that mimic the mono-nuclear copper bound protein intermediates proposed during the formation of the binuclear Cu2S2 core of the enzyme. These three copper complexes of peptides derived from the metal ion binding loop of the CuA center of the subunit II of cytochrome c oxidase showed novel spectroscopic properties which have not so far been reported in any stable small complex.
Collapse
Affiliation(s)
- Dwaipayan Dutta Gupta
- Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005, India.
| | | | | |
Collapse
|
35
|
Nóbrega CS, Saraiva IH, Carreira C, Devreese B, Matzapetakis M, Pauleta SR. The solution structure of the soluble form of the lipid-modified azurin from Neisseria gonorrhoeae , the electron donor of cytochrome c peroxidase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:169-176. [DOI: 10.1016/j.bbabio.2015.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 10/25/2015] [Accepted: 11/13/2015] [Indexed: 12/26/2022]
|
36
|
Pérez-Henarejos SA, Alcaraz LA, Donaire A. Blue Copper Proteins: A rigid machine for efficient electron transfer, a flexible device for metal uptake. Arch Biochem Biophys 2015; 584:134-48. [DOI: 10.1016/j.abb.2015.08.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 08/24/2015] [Accepted: 08/28/2015] [Indexed: 10/23/2022]
|
37
|
Loop recognition and copper-mediated disulfide reduction underpin metal site assembly of CuA in human cytochrome oxidase. Proc Natl Acad Sci U S A 2015; 112:11771-6. [PMID: 26351686 DOI: 10.1073/pnas.1505056112] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Maturation of cytochrome oxidases is a complex process requiring assembly of several subunits and adequate uptake of the metal cofactors. Two orthologous Sco proteins (Sco1 and Sco2) are essential for the correct assembly of the dicopper CuA site in the human oxidase, but their function is not fully understood. Here, we report an in vitro biochemical study that shows that Sco1 is a metallochaperone that selectively transfers Cu(I) ions based on loop recognition, whereas Sco2 is a copper-dependent thiol reductase of the cysteine ligands in the oxidase. Copper binding to Sco2 is essential to elicit its redox function and as a guardian of the reduced state of its own cysteine residues in the oxidizing environment of the mitochondrial intermembrane space (IMS). These results provide a detailed molecular mechanism for CuA assembly, suggesting that copper and redox homeostasis are intimately linked in the mitochondrion.
Collapse
|
38
|
Giannotti MI, Cabeza de Vaca I, Artés JM, Sanz F, Guallar V, Gorostiza P. Direct Measurement of the Nanomechanical Stability of a Redox Protein Active Site and Its Dependence upon Metal Binding. J Phys Chem B 2015; 119:12050-8. [DOI: 10.1021/acs.jpcb.5b06382] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marina I. Giannotti
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28029, Spain
- Physical
Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain
- Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, Barcelona 08028, Spain
| | - Israel Cabeza de Vaca
- Joint
BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, Jordi Girona 29, Barcelona 08034, Spain
| | - Juan M. Artés
- Physical
Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain
- Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, Barcelona 08028, Spain
| | - Fausto Sanz
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28029, Spain
- Physical
Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain
- Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, Barcelona 08028, Spain
| | - Victor Guallar
- Joint
BSC-CRG-IRB Research Program in Computational Biology, Barcelona Supercomputing Center, Jordi Girona 29, Barcelona 08034, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona 08010, Spain
| | - Pau Gorostiza
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28029, Spain
- Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 15-21, Barcelona 08028, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona 08010, Spain
| |
Collapse
|
39
|
Amdursky N, Sepunaru L, Raichlin S, Pecht I, Sheves M, Cahen D. Electron Transfer Proteins as Electronic Conductors: Significance of the Metal and Its Binding Site in the Blue Cu Protein, Azurin. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2015; 2:1400026. [PMID: 27980928 PMCID: PMC5115354 DOI: 10.1002/advs.201400026] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/08/2015] [Indexed: 05/07/2023]
Abstract
Electron transfer (ET) proteins are biomolecules with specific functions, selected by evolution. As such they are attractive candidates for use in potential bioelectronic devices. The blue copper protein azurin (Az) is one of the most-studied ET proteins. Traditional spectroscopic, electrochemical, and kinetic methods employed for studying ET to/from the protein's Cu ion have been complemented more recently by studies of electrical conduction through a monolayer of Az in the solid-state, sandwiched between electrodes. As the latter type of measurement does not require involvement of a redox process, it also allows monitoring electronic transport (ETp) via redox-inactive Az-derivatives. Here, results of macroscopic ETp via redox-active and -inactive Az derivatives, i.e., Cu(II) and Cu(I)-Az, apo-Az, Co(II)-Az, Ni(II)-Az, and Zn(II)-Az are reported and compared. It is found that earlier reported temperature independence of ETp via Cu(II)-Az (from 20 K until denaturation) is unique, as ETp via all other derivatives is thermally activated at temperatures >≈200 K. Conduction via Cu(I)-Az shows unexpected temperature dependence >≈200 K, with currents decreasing at positive and increasing at negative bias. Taking all the data together we find a clear compensation effect of Az conduction around the Az denaturation temperature. This compensation can be understood by viewing the Az binding site as an electron trap, unless occupied by Cu(II), as in the native protein, with conduction of the native protein setting the upper transport efficiency limit.
Collapse
Affiliation(s)
- Nadav Amdursky
- Departments of Materials and Interfaces Weizmann Institute of Science Rehovot 76100 Israel; Departments of Organic Chemistry Weizmann Institute of Science Rehovot 76100 Israel
| | - Lior Sepunaru
- Departments of Materials and Interfaces Weizmann Institute of Science Rehovot 76100 Israel
| | - Sara Raichlin
- Departments of Materials and Interfaces Weizmann Institute of Science Rehovot 76100 Israel; Departments of Organic Chemistry Weizmann Institute of Science Rehovot 76100 Israel
| | - Israel Pecht
- Departments of Immunology Weizmann Institute of Science Rehovot 76100 Israel
| | - Mordechai Sheves
- Departments of Organic Chemistry Weizmann Institute of Science Rehovot 76100 Israel
| | - David Cahen
- Departments of Materials and Interfaces Weizmann Institute of Science Rehovot 76100 Israel
| |
Collapse
|
40
|
Zampino AP, Masters FM, Bladholm EL, Panzner MJ, Berry SM, Leeper TC, Ziegler CJ. Mercury metallation of the copper protein azurin and structural insight into possible heavy metal reactivity. J Inorg Biochem 2014; 141:152-160. [DOI: 10.1016/j.jinorgbio.2014.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 09/05/2014] [Accepted: 09/05/2014] [Indexed: 01/17/2023]
|
41
|
Xi Z, Shi C, Tian C, Liu Y. Conserved residue modulates copper-binding properties through structural dynamics in human copper chaperone Atox1. Metallomics 2014; 5:1566-73. [PMID: 24056613 DOI: 10.1039/c3mt00190c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The human copper chaperone Atox1 plays a central role in the transport of copper in cells. It has been reported that the conserved residue Lys60 contributes to the heterocomplex stability of Atox1 with its target protein ATPase, and that the K60A mutation could diminish the copper transfer. In this work, we carried out the structure determination and dynamic analysis of Atox1 with the K60A mutation in order to elucidate the role of the conserved residue Lys60 in the copper transport. Results show that the K60A mutation results in crucial secondary structure rearrangements and side-chain orientation alteration of the metal-binding residues in Atox1. Protein dynamic studies reveal that the K60A mutation leads to increased overall flexibility, and a significant difference in dynamic properties of the metal-binding sites. The structure and dynamic changes cause a decrease in the copper-binding stability of the K60A mutant. In addition, Cu(i)-mediated hetero-protein interactions with ATP7A are present in the metal transfer of both Atox1 variants, although copper transfer is accompanied with smaller structural alteration in the K60A mutant. These results indicate that Lys60 is crucial in maintaining the structure and dynamic properties of Atox1.
Collapse
Affiliation(s)
- Zhaoyong Xi
- CAS Key Laboratory of Soft Matter Chemistry and Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | | | | | | |
Collapse
|
42
|
Clark KM, Yu Y, van der Donk WA, Blackburn N, Lu Y. Modulating the Copper-Sulfur Interaction in Type 1 Blue Copper Azurin by Replacing Cys112 with Nonproteinogenic Homocysteine. Inorg Chem Front 2014; 1:153-158. [PMID: 24707355 PMCID: PMC3972132 DOI: 10.1039/c3qi00096f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The Cu-SCys interaction is known to play a dominant role in defining the type 1 (T1) blue copper center with respect to both its electronic structure and electron transfer function. Despite this importance, its role has yet to be probed by mutagenesis studies without dramatic change of its T1 copper character. We herein report replacement of the conserved Cys112 in azurin with the nonproteinogenic amino acid homocysteine. Based on electronic absorption, electron paramagnetic resonance, and extended x-ray absorption fine structural spectroscopic studies, this variant displays typical type 1 copper site features. Surprisingly, instead of increasing the strength of the Cu-sulfur interaction by the introduction of the extra methylene group, the Cys112Hcy azurin showed a decrease in the covalent interaction between SHcy and Cu(II) when compared with the WT SCys-Cu(II) interaction. This is likely due to geometric adjustment of the center that resulted in the copper ion moving out of the trigonal plane defined by two histidines and one Hcy and closer to Met121. These structural changes resulted in an increase of reduction potential by 35 mV, consistent with lower Cu-S covalency. These results suggest that the Cu-SCys interaction is close to being optimal in native blue copper protein. It also demonstrates the power of using nonproteinogenic amino acids in addressing important issues in bioinorganic chemistry.
Collapse
Affiliation(s)
- Kevin M Clark
- University of Illinois-Urbana, Department of Biochemistry, Urbana, IL61801; USA
| | - Yang Yu
- University of Illinois-Urbana. Center for Biophysics and Computational Biology, Urbana, IL 61801, USA
| | - Wilfred A van der Donk
- University of Illinois-Urbana, Department of Biochemistry, Urbana, IL61801; USA
- University of Illinois-Urbana. Center for Biophysics and Computational Biology, Urbana, IL 61801, USA
- University of Illinois-Urbana. Department of Chemistry, Urbana, IL 61801, USA
- Howard Hughes Medical Institute, Urbana, IL 61801, USA
| | - Ninian Blackburn
- Oregon Health & Sciences University, Institute of Environmental Health, Beaverton, OR 97006, USA
| | - Yi Lu
- University of Illinois-Urbana, Department of Biochemistry, Urbana, IL61801; USA
- University of Illinois-Urbana. Center for Biophysics and Computational Biology, Urbana, IL 61801, USA
- University of Illinois-Urbana. Department of Chemistry, Urbana, IL 61801, USA
| |
Collapse
|
43
|
Abriata LA, Vila AJ, Dal Peraro M. Molecular dynamics simulations of apocupredoxins: insights into the formation and stabilization of copper sites under entatic control. J Biol Inorg Chem 2014; 19:565-75. [PMID: 24477946 DOI: 10.1007/s00775-014-1108-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 12/30/2013] [Indexed: 10/25/2022]
Abstract
Cupredoxins perform copper-mediated long-range electron transfer (ET) in biological systems. Their copper-binding sites have evolved to force copper ions into ET-competent systems with decreased reorganization energy, increased reduction potential, and a distinct electronic structure compared with those of non-ET-competent copper complexes. The entatic or rack-induced state hypothesis explains these special properties in terms of the strain that the protein matrix exerts on the metal ions. This idea is supported by X-ray structures of apocupredoxins displaying "closed" arrangements of the copper ligands like those observed in the holoproteins; however, it implies completely buried copper-binding atoms, conflicting with the notion that they must be exposed for copper loading. On the other hand, a recent work based on NMR showed that the copper-binding regions of apocupredoxins are flexible in solution. We have explored five cupredoxins in their "closed" apo forms through molecular dynamics simulations. We observed that prearranged ligand conformations are not stable as the X-ray data suggest, although they do form part of the dynamic landscape of the apoproteins. This translates into variable flexibility of the copper-binding regions within a rigid fold, accompanied by fluctuations of the hydrogen bonds around the copper ligands. Major conformations with solvent-exposed copper-binding atoms could allow initial binding of the copper ions. An eventual subsequent incursion to the closed state would result in binding of the remaining ligands, trapping the closed conformation thanks to the additional binding energy and the fastening of noncovalent interactions that make up the rack.
Collapse
Affiliation(s)
- Luciano A Abriata
- Laboratory of Biomolecular Modeling, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland,
| | | | | |
Collapse
|
44
|
Alvarez-Paggi D, Abriata LA, Murgida DH, Vila AJ. Native Cu(A) redox sites are largely resilient to pH variations within a physiological range. Chem Commun (Camb) 2013; 49:5381-3. [PMID: 23652317 DOI: 10.1039/c3cc40457a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Previous studies on engineered CuA centres have shown that one of the histidine ligands is protonated and dissociated from the metal site at physiological pH values, thus suggesting a role in regulating proton-coupled electron transfer of cytochrome c oxidases in vivo. Here we report that for native CuA such protonation does not take place at physiologically relevant pH values and, furthermore, no significant changes in the spectroscopic and redox properties of the metal site occur at low pH.
Collapse
Affiliation(s)
- Damián Alvarez-Paggi
- INQUIMAE-CONICET and Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria Pab. 2, C1428EHA Buenos Aires, Argentina
| | | | | | | |
Collapse
|
45
|
Warren JJ, Gray HB, Winkler JR, Kozak JJ. Euclidean perspective on the unfolding of azurin: angular correlations. Mol Phys 2013. [DOI: 10.1080/00268976.2013.787153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
46
|
Hoffmann A, Binder S, Jesser A, Haase R, Flörke U, Gnida M, Salomone Stagni M, Meyer-Klaucke W, Lebsanft B, Grünig LE, Schneider S, Hashemi M, Goos A, Wetzel A, Rübhausen M, Herres-Pawlis S. Den entatischen Zustand im Griff - ein Duo von Kupfer-Komplexen. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201306061] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
47
|
Hoffmann A, Binder S, Jesser A, Haase R, Flörke U, Gnida M, Salomone Stagni M, Meyer-Klaucke W, Lebsanft B, Grünig LE, Schneider S, Hashemi M, Goos A, Wetzel A, Rübhausen M, Herres-Pawlis S. Catching an Entatic State-A Pair of Copper Complexes. Angew Chem Int Ed Engl 2013; 53:299-304. [DOI: 10.1002/anie.201306061] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 08/25/2013] [Indexed: 11/08/2022]
|
48
|
Argüello JM, Raimunda D, Padilla-Benavides T. Mechanisms of copper homeostasis in bacteria. Front Cell Infect Microbiol 2013; 3:73. [PMID: 24205499 PMCID: PMC3817396 DOI: 10.3389/fcimb.2013.00073] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 10/17/2013] [Indexed: 01/27/2023] Open
Abstract
Copper is an important micronutrient required as a redox co-factor in the catalytic centers of enzymes. However, free copper is a potential hazard because of its high chemical reactivity. Consequently, organisms exert a tight control on Cu(+) transport (entry-exit) and traffic through different compartments, ensuring the homeostasis required for cuproprotein synthesis and prevention of toxic effects. Recent studies based on biochemical, bioinformatics, and metalloproteomics approaches, reveal a highly regulated system of transcriptional regulators, soluble chaperones, membrane transporters, and target cuproproteins distributed in the various bacterial compartments. As a result, new questions have emerged regarding the diversity and apparent redundancies of these components, their irregular presence in different organisms, functional interactions, and resulting system architectures.
Collapse
Affiliation(s)
- José M Argüello
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute Worcester, MA, USA
| | | | | |
Collapse
|
49
|
Abriata LA, Vila AJ. Redox-state sensing by hydrogen bonds in the CuA center of cytochrome c oxidase. J Inorg Biochem 2013; 132:18-20. [PMID: 24012017 DOI: 10.1016/j.jinorgbio.2013.07.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 07/18/2013] [Accepted: 07/23/2013] [Indexed: 11/25/2022]
Abstract
Cytochrome c oxidases (CcO) couple electron transfer to active proton translocation through a gated mechanism that minimizes energy losses by preventing protons from flowing backwards or leaking. Such a complex mechanism requires that information about the redox and protonation states of the different centers be transmitted between different parts of the oxidase. Here we report a network of residues located around the electron entry point of CcO, the CuA site in subunit II, that experience collective pH equilibria around neutral pH. This network starts at the occluded side of the CuA site and extends to the interface between subunits I and II of the CcO, where the proton exit is located and through which electrons flow into subunit I. One of the residues in this network is directly involved in a hydrogen bond to one of the CuA ligands, whose strength is highly sensitive to the redox state of the metal center. We propose that this interaction mediates the transmission of redox changes from ET centers to other functional regions of the oxidase, and possibly also in other similar machineries, as part of their gating and regulatory mechanisms.
Collapse
Affiliation(s)
- Luciano A Abriata
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) and Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Alejandro J Vila
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR) and Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
| |
Collapse
|
50
|
Kaur R, Bren KL. Redox state dependence of axial ligand dynamics in Nitrosomonas europaea cytochrome c552. J Phys Chem B 2013; 117:15720-8. [PMID: 23909651 DOI: 10.1021/jp4064577] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Analysis of NMR spectra reveals that the heme axial Met ligand orientation and dynamics in Nitrosomonas europaea cytochrome c552 (Ne cyt c) are dependent on the heme redox state. In the oxidized state, the heme axial Met is fluxional, interconverting between two conformers related to each other by inversion through the Met δS atom. In the reduced state, there is no evidence of fluxionality, with the Met occupying one conformation similar to that seen in the homologous Pseudomonas aeruginosa cytochrome c551. Comparison of the observed and calculated pseudocontact shifts for oxidized Ne cyt c using the reduced protein structure as a reference structure reveals a redox-dependent change in the structure of the loop bearing the axial Met (loop 3). Analysis of nuclear Overhauser effects (NOEs) and existing structural data provides further support for the redox state dependence of the loop 3 structure. Implications for electron transfer function are discussed.
Collapse
Affiliation(s)
- Ravinder Kaur
- Center for Infectious Disease and Immunology, Research Institute, Rochester General Hospital , Rochester, New York 14621, United States
| | | |
Collapse
|