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Hoffnagle AM, Tezcan FA. Atomically Accurate Design of Metalloproteins with Predefined Coordination Geometries. J Am Chem Soc 2023; 145:14208-14214. [PMID: 37352018 PMCID: PMC10439731 DOI: 10.1021/jacs.3c04047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2023]
Abstract
We report a new computational protein design method for the construction of oligomeric protein assemblies around metal centers with predefined coordination geometries. We apply this method to design two homotrimeric assemblies, Tet4 and TP1, with tetrahedral and trigonal-pyramidal tris(histidine) metal coordination geometries, respectively, and demonstrate that both assemblies form the targeted metal centers with ≤0.2 Å accuracy. Although Tet4 and TP1 are constructed from the same parent protein building block, they are distinct in terms of their overall architectures, the environment surrounding the metal centers, and their metal-based reactivities, illustrating the versatility of our approach.
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Affiliation(s)
- Alexander M. Hoffnagle
- Department of Chemistry and Biochemistry, University of California, San Diego, CA 92093, USA
| | - F. Akif Tezcan
- Department of Chemistry and Biochemistry, University of California, San Diego, CA 92093, USA
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2
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Chino M, Di Costanzo LF, Leone L, La Gatta S, Famulari A, Chiesa M, Lombardi A, Pavone V. Designed Rubredoxin miniature in a fully artificial electron chain triggered by visible light. Nat Commun 2023; 14:2368. [PMID: 37185349 PMCID: PMC10130062 DOI: 10.1038/s41467-023-37941-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 04/06/2023] [Indexed: 05/17/2023] Open
Abstract
Designing metal sites into de novo proteins has significantly improved, recently. However, identifying the minimal coordination spheres, able to encompass the necessary information for metal binding and activity, still represents a great challenge, today. Here, we test our understanding with a benchmark, nevertheless difficult, case. We assemble into a miniature 28-residue protein, the quintessential elements required to fold properly around a FeCys4 redox center, and to function efficiently in electron-transfer. This study addresses a challenge in de novo protein design, as it reports the crystal structure of a designed tetra-thiolate metal-binding protein in sub-Å agreement with the intended design. This allows us to well correlate structure to spectroscopic and electrochemical properties. Given its high reduction potential compared to natural and designed FeCys4-containing proteins, we exploit it as terminal electron acceptor of a fully artificial chain triggered by visible light.
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Affiliation(s)
- Marco Chino
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy
| | - Luigi Franklin Di Costanzo
- Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055, Portici, Italy
| | - Linda Leone
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy
| | - Salvatore La Gatta
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy
| | - Antonino Famulari
- Department of Chemistry, University of Torino, Via Giuria 9, 10125, Torino, Italy
- Department of Condensed Matter Physics, University of Zaragoza, Calle Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - Mario Chiesa
- Department of Chemistry, University of Torino, Via Giuria 9, 10125, Torino, Italy
| | - Angela Lombardi
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy.
| | - Vincenzo Pavone
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, 80126, Napoli, Italy.
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3
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Koebke KJ, Pinter TBJ, Pitts WC, Pecoraro VL. Catalysis and Electron Transfer in De Novo Designed Metalloproteins. Chem Rev 2022; 122:12046-12109. [PMID: 35763791 PMCID: PMC10735231 DOI: 10.1021/acs.chemrev.1c01025] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
One of the hallmark advances in our understanding of metalloprotein function is showcased in our ability to design new, non-native, catalytically active protein scaffolds. This review highlights progress and milestone achievements in the field of de novo metalloprotein design focused on reports from the past decade with special emphasis on de novo designs couched within common subfields of bioinorganic study: heme binding proteins, monometal- and dimetal-containing catalytic sites, and metal-containing electron transfer sites. Within each subfield, we highlight several of what we have identified as significant and important contributions to either our understanding of that subfield or de novo metalloprotein design as a discipline. These reports are placed in context both historically and scientifically. General suggestions for future directions that we feel will be important to advance our understanding or accelerate discovery are discussed.
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Affiliation(s)
- Karl J. Koebke
- Department of Chemistry, University of Michigan Ann Arbor, MI 48109 USA
| | | | - Winston C. Pitts
- Department of Chemistry, University of Michigan Ann Arbor, MI 48109 USA
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Boncella AE, Sabo ET, Santore RM, Carter J, Whalen J, Hudspeth JD, Morrison CN. The expanding utility of iron-sulfur clusters: Their functional roles in biology, synthetic small molecules, maquettes and artificial proteins, biomimetic materials, and therapeutic strategies. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214229] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Unravelling the Structure of the Tetrahedral Metal-Binding Site in METP3 through an Experimental and Computational Approach. Molecules 2021; 26:molecules26175221. [PMID: 34500655 PMCID: PMC8434281 DOI: 10.3390/molecules26175221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 11/17/2022] Open
Abstract
Understanding the structural determinants for metal ion coordination in metalloproteins is a fundamental issue for designing metal binding sites with predetermined geometry and activity. In order to achieve this, we report in this paper the design, synthesis and metal binding properties of METP3, a homodimer made up of a small peptide, which self assembles in the presence of tetrahedrally coordinating metal ions. METP3 was obtained through a redesign approach, starting from the previously developed METP molecule. The undecapeptide sequence of METP, which dimerizes to house a Cys4 tetrahedral binding site, was redesigned in order to accommodate a Cys2His2 site. The binding properties of METP3 were determined toward different metal ions. Successful assembly of METP3 with Co(II), Zn(II) and Cd(II), in the expected 2:1 stoichiometry and tetrahedral geometry was proven by UV-visible spectroscopy. CD measurements on both the free and metal-bound forms revealed that the metal coordination drives the peptide chain to fold into a turned conformation. Finally, NMR data of the Zn(II)-METP3 complex, together with a retrostructural analysis of the Cys-X-X-His motif in metalloproteins, allowed us to define the model structure. All the results establish the suitability of the short METP sequence for accommodating tetrahedral metal binding sites, regardless of the first coordination ligands.
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Das D, Ainavarapu SRK. Azurin-Derived Peptides: Comparison of Nickel- and Copper-Binding Properties. Inorg Chem 2021; 60:9720-9726. [PMID: 34137603 DOI: 10.1021/acs.inorgchem.1c01007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metalloproteins are an important class of proteins involved in metal uptake, transport, and electron-transfer reactions. Mimicking the active sites of these proteins through miniaturization is an active area of research with applications in biotechnology and medicine. Azurin is a 128-residue copper-binding cupredoxin protein involved in electron-transfer reactions. Previous studies have reported on the copper-binding-induced spectroscopic and structural properties of peptide loops (11 and 13 residues) from azurin. These azurin peptides exhibited novel stoichiometries. However, the underlying mechanism of fluorescence quenching upon copper binding remains to be understood, whether it is due to electron transfer, energy transfer, or both. Here, we report nickel-binding-associated spectroscopic and structural properties of the azurin peptides. They develop a β-turn upon nickel binding as seen in circular dichroism and exhibit electronic transitions centered at 270 and 450 nm. Unlike copper, which exhibited 1:1 and 1:2 peptide:metal stoichiometries, nickel exhibited only a 1:1 stoichiometry. Tryptophan-containing peptides showed fluorescence quenching upon nickel binding, which is due to electron transfer. These results further suggest that the quenching in copper-bound peptides is also due to electron transfer, which could not be ascertained in previous studies. Overall, azurin peptides provide a platform for studying metal-induced structural and spectroscopic properties using transition-metal ions.
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Affiliation(s)
- Debanjana Das
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Dr. Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Sri Rama Koti Ainavarapu
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Dr. Homi Bhabha Road, Colaba, Mumbai 400005, India
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Abstract
The field of de novo protein design has met with considerable success over the past few decades. Heme, a cofactor, has often been introduced to impart a diverse array of functions to a protein, ranging from electron transport to respiration. In nature, heme is found to occur predominantly in α-helical structures over β-sheets, which has resulted in significant designs of heme proteins utilizing coiled-coil helices. By contrast, there are only a few known β-sheet proteins that bind heme and designs of β-sheets frequently result in amyloid-like aggregates. This review reflects on our success in designing a series of multistranded β-sheet heme binding peptides that are well folded in both aqueous and membrane-like environments. Initially, we designed a β-hairpin peptide that self-assembles to bind heme and performs peroxidase activity in membrane. The β-hairpin was optimized further to accommodate a heme binding pocket within multistranded β-sheets for catalysis and electron transfer in membranes. Furthermore, we de novo designed and characterized β-sheet peptides and miniproteins that are soluble in an aqueous environment capable of binding single and multiple hemes with high affinity and stability. Collectively, these studies highlight the substantial progress made toward the design of functional β-sheets.
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Affiliation(s)
- Areetha D'Souza
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
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Yoon C, Lee D, Lee SJ. Regulation of the Central Dogma through Bioinorganic Events with Metal Coordination for Specific Interactions. B KOREAN CHEM SOC 2020. [DOI: 10.1002/bkcs.12090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Chungwoon Yoon
- Department of Chemistry Institute for Molecular Biology and Genetics, Jeonbuk National University Jeonju 54896 Republic of Korea
| | - Dong‐Heon Lee
- Department of Chemistry Institute for Molecular Biology and Genetics, Jeonbuk National University Jeonju 54896 Republic of Korea
| | - Seung Jae Lee
- Department of Chemistry Institute for Molecular Biology and Genetics, Jeonbuk National University Jeonju 54896 Republic of Korea
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Leone L, Chino M, Nastri F, Maglio O, Pavone V, Lombardi A. Mimochrome, a metalloporphyrin‐based catalytic Swiss knife†. Biotechnol Appl Biochem 2020; 67:495-515. [DOI: 10.1002/bab.1985] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 07/09/2020] [Indexed: 12/20/2022]
Affiliation(s)
- Linda Leone
- Department of Chemical Sciences University of Napoli “Federico II” Napoli Italy
| | - Marco Chino
- Department of Chemical Sciences University of Napoli “Federico II” Napoli Italy
| | - Flavia Nastri
- Department of Chemical Sciences University of Napoli “Federico II” Napoli Italy
| | - Ornella Maglio
- Department of Chemical Sciences University of Napoli “Federico II” Napoli Italy
- IBB ‐ National Research Council Napoli Italy
| | - Vincenzo Pavone
- Department of Chemical Sciences University of Napoli “Federico II” Napoli Italy
| | - Angela Lombardi
- Department of Chemical Sciences University of Napoli “Federico II” Napoli Italy
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Das D, Mitra S, Kumar R, Banerjee S, Koti Ainavarapu SR. Copper-induced spectroscopic and structural changes in short peptides derived from azurin. Arch Biochem Biophys 2020; 687:108388. [PMID: 32343975 DOI: 10.1016/j.abb.2020.108388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/07/2020] [Accepted: 04/21/2020] [Indexed: 11/26/2022]
Abstract
The active sites of metalloproteins may be mimicked by designing peptides that bind to their respective metal ions. Studying the binding of protein ligands to metal ions along with the associated structural changes is important in understanding metal uptake, transport and electron transfer functions of proteins. Copper-binding metalloprotein azurin is a 128-residue electron transfer protein with a redox-active copper cofactor. Here, we report the copper-binding associated spectroscopic and structural properties of peptide loops (11 and 13 residues) from the copper-binding site of azurin. These peptides develop a β-turn upon copper-binding with a 1:1 Cu2+:peptide stoichiometry as seen in circular dichroism and exhibit electronic transitions centered at 340 nm and 540 nm. Further addition of copper develops a helical feature along with a shift in the absorption maxima to ~360 nm and ~580 nm at 2:1 Cu2+:peptide stoichiometry, indicating stoichiometric dependence of copper-binding geometry. Mass spectrometry indicates the copper-binding to cysteine, histidine and methionine in the peptide with 1:1 stoichiometry, and interestingly, dimerization through a disulfide linkage at 2:1 stoichiometry, as observed previously for denatured azurin. Fluorescence quenching studies on peptides with tryptophan further confirm the copper-binding induced changes in the two peptides are bi-phasic.
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Affiliation(s)
- Debanjana Das
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Dr. Homi Bhabha Road, Colaba, Mumbai, 400005, India
| | - Soumyajit Mitra
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Dr. Homi Bhabha Road, Colaba, Mumbai, 400005, India
| | - Rohit Kumar
- Department of Chemistry, Indian Institute of Science Education and Research Tirupati, Tirupati, 517507, India
| | - Shibdas Banerjee
- Department of Chemistry, Indian Institute of Science Education and Research Tirupati, Tirupati, 517507, India.
| | - Sri Rama Koti Ainavarapu
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Dr. Homi Bhabha Road, Colaba, Mumbai, 400005, India.
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12
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Abstract
Proteins are molecular machines whose function depends on their ability to achieve complex folds with precisely defined structural and dynamic properties. The rational design of proteins from first-principles, or de novo, was once considered to be impossible, but today proteins with a variety of folds and functions have been realized. We review the evolution of the field from its earliest days, placing particular emphasis on how this endeavor has illuminated our understanding of the principles underlying the folding and function of natural proteins, and is informing the design of macromolecules with unprecedented structures and properties. An initial set of milestones in de novo protein design focused on the construction of sequences that folded in water and membranes to adopt folded conformations. The first proteins were designed from first-principles using very simple physical models. As computers became more powerful, the use of the rotamer approximation allowed one to discover amino acid sequences that stabilize the desired fold. As the crystallographic database of protein structures expanded in subsequent years, it became possible to construct proteins by assembling short backbone fragments that frequently recur in Nature. The second set of milestones in de novo design involves the discovery of complex functions. Proteins have been designed to bind a variety of metals, porphyrins, and other cofactors. The design of proteins that catalyze hydrolysis and oxygen-dependent reactions has progressed significantly. However, de novo design of catalysts for energetically demanding reactions, or even proteins that bind with high affinity and specificity to highly functionalized complex polar molecules remains an importnant challenge that is now being achieved. Finally, the protein design contributed significantly to our understanding of membrane protein folding and transport of ions across membranes. The area of membrane protein design, or more generally of biomimetic polymers that function in mixed or non-aqueous environments, is now becoming increasingly possible.
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Walke G, Ruthstein S. Does the ATSM-Cu(II) Biomarker Integrate into the Human Cellular Copper Cycle? ACS OMEGA 2019; 4:12278-12285. [PMID: 31460344 PMCID: PMC6681976 DOI: 10.1021/acsomega.9b01748] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 07/04/2019] [Indexed: 06/10/2023]
Abstract
Hypoxia is commonly encountered in the tumor microenvironment and drives proliferation, angiogenesis, and resistance to therapy. Imaging of hypoxia is important in many disease states in oncology, cardiology, and neurology. Finding clinically approved imaging biomarkers for hypoxia has proved challenging. Candidate biomarkers have shown low uptake into tumors and low signal to background ratios that adversely affect imaging quality. Copper complexes have been identified as potential biomarkers for hypoxia owing to their redox ability. Active uptake of copper complexes into cells could ensure selectivity and high sensitivity. We explored the reactivity and selectivity of the ATSM-Cu(II) biomarker to proteins that are involved in the copper cycle using electron paramagnetic resonance (EPR) spectroscopy and UV-vis measurements. We show that the affinity of the ATSM-Cu(II) complex to proteins in the copper cycle is low and the cell probably does not actively uptake ATSM-Cu(II).
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De novo design of symmetric ferredoxins that shuttle electrons in vivo. Proc Natl Acad Sci U S A 2019; 116:14557-14562. [PMID: 31262814 DOI: 10.1073/pnas.1905643116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A symmetric origin for bacterial ferredoxins was first proposed over 50 y ago, yet, to date, no functional symmetric molecule has been constructed. It is hypothesized that extant proteins have drifted from their symmetric roots via gene duplication followed by mutations. Phylogenetic analyses of extant ferredoxins support the independent evolution of N- and C-terminal sequences, thereby allowing consensus-based design of symmetric 4Fe-4S molecules. All designs bind two [4Fe-4S] clusters and exhibit strongly reducing midpoint potentials ranging from -405 to -515 mV. One of these constructs efficiently shuttles electrons through a designed metabolic pathway in Escherichia coli These finding establish that ferredoxins consisting of a symmetric core can be used as a platform to design novel electron transfer carriers for in vivo applications. Outer-shell asymmetry increases sequence space without compromising electron transfer functionality.
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Lombardi A, Pirro F, Maglio O, Chino M, DeGrado WF. De Novo Design of Four-Helix Bundle Metalloproteins: One Scaffold, Diverse Reactivities. Acc Chem Res 2019; 52:1148-1159. [PMID: 30973707 DOI: 10.1021/acs.accounts.8b00674] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
De novo protein design represents an attractive approach for testing and extending our understanding of metalloprotein structure and function. Here, we describe our work on the design of DF (Due Ferri or two-iron in Italian), a minimalist model for the active sites of much larger and more complex natural diiron and dimanganese proteins. In nature, diiron and dimanganese proteins protypically bind their ions in 4-Glu, 2-His environments, and they catalyze diverse reactions, ranging from hydrolysis, to O2-dependent chemistry, to decarbonylation of aldehydes. In the design of DF, the position of each atom-including the backbone, the first-shell ligands, the second-shell hydrogen-bonded groups, and the well-packed hydrophobic core-was bespoke using precise mathematical equations and chemical principles. The first member of the DF family was designed to be of minimal size and complexity and yet to display the quintessential elements required for binding the dimetal cofactor. After thoroughly characterizing its structural, dynamic, spectroscopic, and functional properties, we added additional complexity in a rational stepwise manner to achieve increasingly sophisticated catalytic functions, ultimately demonstrating substrate-gated four-electron reduction of O2 to water. We also briefly describe the extension of these studies to the design of proteins that bind nonbiological metal cofactors (a synthetic porphyrin and a tetranuclear cluster), and a Zn2+/proton antiporting membrane protein. Together these studies demonstrate a successful and generally applicable strategy for de novo metalloprotein design, which might indeed mimic the process by which primordial metalloproteins evolved. We began the design process with a highly symmetrical backbone and binding site, by using point-group symmetry to assemble the secondary structures that position the amino acid side chains required for binding. The resulting models provided a rough starting point and initial parameters for the subsequent precise design of the final protein using modern methods of computational protein design. Unless the desired site is itself symmetrical, this process requires reduction of the symmetry or lifting it altogether. Nevertheless, the initial symmetrical structure can be helpful to restrain the search space during assembly of the backbone. Finally, the methods described here should be generally applicable to the design of highly stable and robust catalysts and sensors. There is considerable potential in combining the efficiency and knowledge base associated with homogeneous metal catalysis with the programmability, biocompatibility, and versatility of proteins. While the work reported here focuses on testing and learning the principles of natural metalloproteins by designing and studying proteins one at a time, there is also considerable potential for using designed proteins that incorporate both biological and nonbiological metal ion cofactors for the evolution of novel catalysts.
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Affiliation(s)
- Angela Lombardi
- Department of Chemical Sciences, University of Napoli Federico II, Via Cintia, 26, 80126 Napoli, Italy
| | - Fabio Pirro
- Department of Chemical Sciences, University of Napoli Federico II, Via Cintia, 26, 80126 Napoli, Italy
- Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California 94158-9001, United States
| | - Ornella Maglio
- Department of Chemical Sciences, University of Napoli Federico II, Via Cintia, 26, 80126 Napoli, Italy
- IBB, National Research Council, Via Mezzocannone 16, 80134 Napoli, Italy
| | - Marco Chino
- Department of Chemical Sciences, University of Napoli Federico II, Via Cintia, 26, 80126 Napoli, Italy
| | - William F. DeGrado
- Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California 94158-9001, United States
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Rittle J, Field MJ, Green MT, Tezcan FA. An efficient, step-economical strategy for the design of functional metalloproteins. Nat Chem 2019; 11:434-441. [PMID: 30778140 PMCID: PMC6483823 DOI: 10.1038/s41557-019-0218-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 01/11/2019] [Indexed: 01/31/2023]
Abstract
The bottom-up design and construction of functional metalloproteins remains a formidable task in biomolecular design. Although numerous strategies have been used to create new metalloproteins, pre-existing knowledge of the tertiary and quaternary protein structure is often required to generate suitable platforms for robust metal coordination and activity. Here we report an alternative and easily implemented approach (metal active sites by covalent tethering or MASCoT) in which folded protein building blocks are linked by a single disulfide bond to create diverse metal coordination environments within evolutionarily naive protein-protein interfaces. Metalloproteins generated using this strategy uniformly bind a wide array of first-row transition metal ions (MnII, FeII, CoII, NiII, CuII, ZnII and vanadyl) with physiologically relevant thermodynamic affinities (dissociation constants ranging from 700 nM for MnII to 50 fM for CuII). MASCoT readily affords coordinatively unsaturated metal centres-including a penta-His-coordinated non-haem Fe site-and well-defined binding pockets that can accommodate modifications and enable coordination of exogenous ligands such as nitric oxide to the interfacial metal centre.
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Affiliation(s)
- Jonathan Rittle
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Mackenzie J Field
- Department of Chemistry, University of California, Irvine, Irvine, CA, USA
| | - Michael T Green
- Department of Chemistry, University of California, Irvine, Irvine, CA, USA
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA
| | - F Akif Tezcan
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA.
- Materials Science and Engineering, University of California, San Diego, La Jolla, CA, USA.
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Leone L, D'Alonzo D, Balland V, Zambrano G, Chino M, Nastri F, Maglio O, Pavone V, Lombardi A. Mn-Mimochrome VI *a: An Artificial Metalloenzyme With Peroxygenase Activity. Front Chem 2018; 6:590. [PMID: 30564568 PMCID: PMC6288486 DOI: 10.3389/fchem.2018.00590] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/13/2018] [Indexed: 12/27/2022] Open
Abstract
Manganese-porphyrins are important tools in catalysis, due to their capability to promote a wide variety of synthetically valuable transformations. Despite their great reactivity, the difficulties to control the reaction selectivity and to protect the catalyst from self-degradation hamper their practical application. Compared to small-molecule porphyrin complexes, metalloenzymes display remarkable features, because the reactivity of the metal center is finely modulated by a complex interplay of interactions within the protein matrix. In the effort to combine the catalytic potential of manganese porphyrins with the unique properties of biological catalysts, artificial metalloenzymes have been reported, mainly by incorporation of manganese-porphyrins into native protein scaffolds. Here we describe the spectroscopic and catalytic properties of Mn-Mimochrome VI*a (Mn-MC6*a), a mini-protein with a manganese deuteroporphyrin active site within a scaffold of two synthetic peptides covalently bound to the porphyrin. Mn-MC6*a is an efficient catalyst endowed with peroxygenase activity. The UV-vis absorption spectrum of Mn-MC6*a resembles that of Mn-reconstituted horseradish peroxidase (Mn-HRP), both in the resting and high-valent oxidized states. Remarkably, Mn-MC6*a shows a higher reactivity compared to Mn-HRP, because higher yields and chemoselectivity were observed in thioether oxidation. Experimental evidences also provided indications on the nature of the high-valent reactive intermediate and on the sulfoxidation mechanism.
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Affiliation(s)
- Linda Leone
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
| | - Daniele D'Alonzo
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
| | - Véronique Balland
- Laboratoire d'Electrochimie Moléculaire, UMR 7591 CNRS, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Gerardo Zambrano
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
| | - Marco Chino
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
| | - Flavia Nastri
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
| | - Ornella Maglio
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
- Institute of Biostructures and Bioimages, National Research Council, Naples, Italy
| | - Vincenzo Pavone
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
| | - Angela Lombardi
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
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18
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Perrella F, Raucci U, Chiariello MG, Chino M, Maglio O, Lombardi A, Rega N. Unveiling the structure of a novel artificial heme-enzyme with peroxidase-like activity: A theoretical investigation. Biopolymers 2018; 109:e23225. [DOI: 10.1002/bip.23225] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/11/2018] [Accepted: 04/25/2018] [Indexed: 01/29/2023]
Affiliation(s)
- Fulvio Perrella
- Dipartimento di Scienze Chimiche; Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia; Napoli 80126 Italy
| | - Umberto Raucci
- Dipartimento di Scienze Chimiche; Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia; Napoli 80126 Italy
| | - Maria Gabriella Chiariello
- Dipartimento di Scienze Chimiche; Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia; Napoli 80126 Italy
| | - Marco Chino
- Dipartimento di Scienze Chimiche; Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia; Napoli 80126 Italy
| | - Ornella Maglio
- Dipartimento di Scienze Chimiche; Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia; Napoli 80126 Italy
- IBB-CNR, Via Mezzocannone 16; Napoli 80134 Italy
| | - Angela Lombardi
- Dipartimento di Scienze Chimiche; Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia; Napoli 80126 Italy
| | - Nadia Rega
- Dipartimento di Scienze Chimiche; Università di Napoli Federico II, Complesso Universitario di M.S.Angelo, via Cintia; Napoli 80126 Italy
- CRIB Center for Advanced Biomaterials for Healthcare, Piazzale Tecchio; Napoli 80125 Italy
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Zhang SQ, Chino M, Liu L, Tang Y, Hu X, DeGrado WF, Lombardi A. De Novo Design of Tetranuclear Transition Metal Clusters Stabilized by Hydrogen-Bonded Networks in Helical Bundles. J Am Chem Soc 2018; 140:1294-1304. [PMID: 29249157 PMCID: PMC5860638 DOI: 10.1021/jacs.7b08261] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
De novo design provides an attractive approach to test the mechanism by which metalloproteins define the geometry and reactivity of their metal ion cofactors. While there has been considerable progress in designing proteins that bind transition metal ions including iron-sulfur clusters, the design of tetranuclear clusters with oxygen-rich environments has not been accomplished. Here, we describe the design of tetranuclear clusters, consisting of four Zn2+ and four carboxylate oxygens situated at the vertices of a distorted cube-like structure. The tetra-Zn2+ clusters are bound at a buried site within a four-helix bundle, with each helix donating a single carboxylate (Glu or Asp) and imidazole (His) ligand, as well as second- and third-shell ligands. Overall, the designed site consists of four Zn2+ and 16 polar side chains in a fully connected hydrogen-bonded network. The designed proteins have apolar cores at the top and bottom of the bundle, which drive the assembly of the liganding residues near the center of the bundle. The steric bulk of the apolar residues surrounding the binding site was varied to determine how subtle changes in helix-helix packing affect the binding site. The crystal structures of two of four proteins synthesized were in good agreement with the overall design; both formed a distorted cuboidal site stabilized by flanking second- and third-shell interactions that stabilize the primary ligands. A third structure bound a single Zn2+ in an unanticipated geometry, and the fourth bound multiple Zn2+ at multiple sites at partial occupancy. The metal-binding and conformational properties of the helical bundles in solution, probed by circular dichroism spectroscopy, analytical ultracentrifugation, and NMR, were consistent with the crystal structures.
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Affiliation(s)
- Shao-Qing Zhang
- Department of Chemistry, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104-6396, United States
- Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94158-9001, United States
| | - Marco Chino
- Department of Chemical Sciences, University of Napoli “Federico II”, Via Cintia, 46, I-80126 Napoli, Italy
| | - Lijun Liu
- Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94158-9001, United States
- DLX Scientific, Lawrence, KS 66049, United States
| | - Youzhi Tang
- Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94158-9001, United States
- College of Veterinary Medicine, South China Agricultural University, Guangdong 510642, China
| | - Xiaozhen Hu
- Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94158-9001, United States
| | - William F. DeGrado
- Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94158-9001, United States
| | - Angela Lombardi
- Department of Chemical Sciences, University of Napoli “Federico II”, Via Cintia, 46, I-80126 Napoli, Italy
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Design of Redox-Active Peptides: Towards Functional Materials. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016. [PMID: 27677515 DOI: 10.1007/978-3-319-39196-0_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
In nature, the majority of processes that occur in the cell involve the cycling of electrons and protons, changing the reduction and oxidation state of substrates to alter their chemical reactivity and usefulness in vivo. One of the most relevant examples of these processes is the electron transport chain, a series of oxidoreductase proteins that shuttle electrons through well-defined pathways, concurrently moving protons across the cell membrane. Inspired by these processes, researchers have sought to develop materials to mimic natural systems for a number of applications, including fuel production. The most common cofactors found in proteins to carry out electron transfer are iron sulfur clusters and porphyrin-like molecules. Both types have been studied within natural proteins, such as in photosynthetic machinery or soluble electron carriers; in parallel, an extensive literature has developed over recent years attempting to model and study these cofactors within peptide-based materials. This chapter will focus on major designs that have significantly advanced the field.
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21
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Nastri F, Chino M, Maglio O, Bhagi-Damodaran A, Lu Y, Lombardi A. Design and engineering of artificial oxygen-activating metalloenzymes. Chem Soc Rev 2016; 45:5020-54. [PMID: 27341693 PMCID: PMC5021598 DOI: 10.1039/c5cs00923e] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Many efforts are being made in the design and engineering of metalloenzymes with catalytic properties fulfilling the needs of practical applications. Progress in this field has recently been accelerated by advances in computational, molecular and structural biology. This review article focuses on the recent examples of oxygen-activating metalloenzymes, developed through the strategies of de novo design, miniaturization processes and protein redesign. Considerable progress in these diverse design approaches has produced many metal-containing biocatalysts able to adopt the functions of native enzymes or even novel functions beyond those found in Nature.
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Affiliation(s)
- Flavia Nastri
- Department of Chemical Sciences, University of Naples “Federico II”, Via Cintia, 80126 Naples, Italy
| | - Marco Chino
- Department of Chemical Sciences, University of Naples “Federico II”, Via Cintia, 80126 Naples, Italy
| | - Ornella Maglio
- Department of Chemical Sciences, University of Naples “Federico II”, Via Cintia, 80126 Naples, Italy
- IBB, CNR, Via Mezzocannone 16, 80134 Naples, Italy
| | - Ambika Bhagi-Damodaran
- Department of Chemistry, University of Illinois at Urbana-Champaign, A322 CLSL, 600 South Mathews Avenue, Urbana, IL 61801
| | - Yi Lu
- Department of Chemistry, University of Illinois at Urbana-Champaign, A322 CLSL, 600 South Mathews Avenue, Urbana, IL 61801
| | - Angela Lombardi
- Department of Chemical Sciences, University of Naples “Federico II”, Via Cintia, 80126 Naples, Italy
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22
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Szunyogh D, Gyurcsik B, Larsen FH, Stachura M, Thulstrup PW, Hemmingsen L, Jancsó A. Zn(II) and Hg(II) binding to a designed peptide that accommodates different coordination geometries. Dalton Trans 2015; 44:12576-88. [PMID: 26040991 DOI: 10.1039/c5dt00945f] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Designed metal ion binding peptides offer a variety of applications in both basic science as model systems of more complex metalloproteins, and in biotechnology, e.g. in bioremediation of toxic metal ions, biomining or as artificial enzymes. In this work a peptide (HS: Ac-SCHGDQGSDCSI-NH2) has been specifically designed for binding of both Zn(II) and Hg(II), i.e. metal ions with different preferences in terms of coordination number, coordination geometry, and to some extent ligand composition. It is demonstrated that HS accommodates both metal ions, and the first coordination sphere, metal ion exchange between peptides, and speciation are characterized as a function of pH using UV-absorption-, synchrotron radiation CD-, (1)H-NMR-, and PAC-spectroscopy as well as potentiometry. Hg(II) binds to the peptide with very high affinity in a {HgS2} coordination geometry, bringing together the two cysteinates close to each end of the peptide in a loop structure. Despite the high affinity, Hg(II) is kinetically labile, exchanging between peptides on the subsecond timescale, as indicated by line broadening in (1)H-NMR. The Zn(II)-HS system displays more complex speciation, involving monomeric species with coordinating cysteinates, histidine, and a solvent water molecule, as well as HS-Zn(II)-HS complexes. In summary, the HS peptide displays conformational flexibility, contains many typical metal ion binding groups, and is able to accommodate metal ions with different structural and ligand preferences with high affinity. As such, the HS peptide may be a scaffold offering binding of a variety of metal ions, and potentially serve for metal ion sequestration in biotechnological applications.
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Affiliation(s)
- Dániel Szunyogh
- MTA-SZTE Bioinorganic Chemistry Research Group, Dóm tér 7, Szeged, H-6720, Hungary
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23
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Zimmerman MT, Bayse CA, Ramoutar RR, Brumaghim JL. Sulfur and selenium antioxidants: challenging radical scavenging mechanisms and developing structure-activity relationships based on metal binding. J Inorg Biochem 2014; 145:30-40. [PMID: 25600984 DOI: 10.1016/j.jinorgbio.2014.12.020] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 12/17/2014] [Accepted: 12/19/2014] [Indexed: 11/30/2022]
Abstract
Because sulfur and selenium antioxidants can prevent oxidative damage, numerous animal and clinical trials have investigated the ability of these compounds to prevent the oxidative stress that is an underlying cause of cardiovascular disease, Alzheimer's disease, and cancer, among others. One of the most common sources of oxidative damage is metal-generated hydroxyl radical; however, very little research has focused on determining the metal-binding abilities and structural attributes that affect oxidative damage prevention by sulfur and selenium compounds. In this review, we describe our ongoing investigations into sulfur and selenium antioxidant prevention of iron- and copper-mediated oxidative DNA damage. We determined that many sulfur and selenium compounds inhibit Cu(I)-mediated DNA damage and that DNA damage prevention varies dramatically when Fe(II) is used in place of Cu(I) to generate hydroxyl radical. Oxidation potentials of the sulfur or selenium compounds do not correlate with their ability to prevent DNA damage, highlighting the importance of metal coordination rather than reactive oxygen species scavenging as an antioxidant mechanism. Additional gel electrophoresis, mass spectrometry, and UV-visible studies confirmed sulfur and selenium antioxidant binding to Cu(I) and Fe(II). Ultimately, our studies established that both the hydroxyl-radical-generating metal ion and the chemical environment of the sulfur or selenium significantly affect DNA damage prevention and that metal coordination is an essential mechanism for these antioxidants.
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Affiliation(s)
| | - Craig A Bayse
- Department of Chemistry and Biochemistry, Old Dominion University, Hampton Boulevard, Norfolk, VA 23529, USA
| | - Ria R Ramoutar
- Department of Chemistry, Clemson University, Clemson, SC 29634-0973, USA
| | - Julia L Brumaghim
- Department of Chemistry, Clemson University, Clemson, SC 29634-0973, USA.
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24
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Yu F, Cangelosi VM, Zastrow ML, Tegoni M, Plegaria JS, Tebo AG, Mocny CS, Ruckthong L, Qayyum H, Pecoraro VL. Protein design: toward functional metalloenzymes. Chem Rev 2014; 114:3495-578. [PMID: 24661096 PMCID: PMC4300145 DOI: 10.1021/cr400458x] [Citation(s) in RCA: 340] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Fangting Yu
- University of Michigan, Ann Arbor, Michigan 48109, United States
| | | | | | | | | | - Alison G. Tebo
- University of Michigan, Ann Arbor, Michigan 48109, United States
| | | | - Leela Ruckthong
- University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Hira Qayyum
- University of Michigan, Ann Arbor, Michigan 48109, United States
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25
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Vicari C, Saraiva IH, Maglio O, Nastri F, Pavone V, Louro RO, Lombardi A. Artificial heme-proteins: determination of axial ligand orientations through paramagnetic NMR shifts. Chem Commun (Camb) 2014; 50:3852-5. [DOI: 10.1039/c3cc49123d] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An empirical equation, describing the relationship between paramagnetic shifts and axial ligand orientations has been applied to an artificial bis-histidine ferriheme-protein, in order to determine the geometry of the active site.
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Affiliation(s)
- Claudia Vicari
- Department of Chemical Sciences
- University “Federico II” of Naples
- Naples, Italy
| | | | - Ornella Maglio
- Department of Chemical Sciences
- University “Federico II” of Naples
- Naples, Italy
- IBB-CNR
- Naples, Italy
| | - Flavia Nastri
- Department of Chemical Sciences
- University “Federico II” of Naples
- Naples, Italy
| | - Vincenzo Pavone
- Department of Chemical Sciences
- University “Federico II” of Naples
- Naples, Italy
| | | | - Angela Lombardi
- Department of Chemical Sciences
- University “Federico II” of Naples
- Naples, Italy
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26
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Jacques A, Clémancey M, Blondin G, Fourmond V, Latour JM, Sénèque O. A cyclic peptide-based redox-active model of rubredoxin. Chem Commun (Camb) 2013; 49:2915-7. [DOI: 10.1039/c3cc40517f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Rimola A, Aschi M, Orlando R, Ugliengo P. Does adsorption at hydroxyapatite surfaces induce peptide folding? Insights from large-scale B3LYP calculations. J Am Chem Soc 2012; 134:10899-910. [PMID: 22680347 DOI: 10.1021/ja302262y] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Large-scale periodic quantum mechanical calculations (509 atoms, 7852 atomic orbitals) based on the hybrid B3LYP functional focused on the peptide folding induced by the adsorption on the (001) and (010) hydroxyapatite (HA) surfaces give interesting insights on the role of specific interactions between surface sites and the peptide, which stabilize the helix conformation over the "native" random coil ones for in silico designed model peptides. The two peptides were derived from the 12-Gly oligomer, with one (P1, C-tGGKGGGGGGEGGN-t) and two (P2, C-tGGKGGKEGGEGGN-t) glutamic acid (E) and lysine (K) residue mutations. The most stable gas-phase "native" conformation for both peptides resulted in a random coil (RC) structure, with the helix (H) conformation being ≈100 kJ mol(-1) higher in free energy. The two peptide conformations interact with the HA (001) and (010) surfaces by C═O groups via Ca(2+) ions, by hydrogen bond between NH(2) groups and the basic PO(4)(3-) groups and by a relevant fraction due to dispersion forces. Peptide adsorption was studied on the dry (001) surface, the wet one envisaging 2 H(2)O per surface Ca(2+) and, on the latter, also considering the adsorption of microsolvated peptides with 4 H(2)O molecules located at sites responsible of the interaction with the surface. The P1 mutant does prefer to be adsorbed as a random coil by ≈160 kJ/mol, whereas the reverse is computed for P2, preferring the helix conformation by ≈50 kJ/mol. Adsorption as helix of both P1 and P2 mutants brings about proton transfer toward the HA surfaces with a large charge transfer component to the interaction energy.
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Affiliation(s)
- Albert Rimola
- Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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28
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29
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Botelho HM, Gomes CM. Structural reorganization renders enhanced metalloprotein stability. Chem Commun (Camb) 2011; 47:11149-51. [PMID: 21894348 DOI: 10.1039/c1cc13354c] [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]
Abstract
The enhanced stability of a mesophilic metalloprotein was assessed using biophysical spectroscopies. Significant local structural interconversions during thermal insult account for a reorganization of the protein scaffold, without disturbing the active metal site. This cushioning mechanism is proposed to be a generic property of metalloproteins contributing to enhanced stability.
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Affiliation(s)
- Hugo M Botelho
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. República, EAN 2785-572, Oeiras, Portugal
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30
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Lee SJ, Michalek JL, Besold AN, Rokita SE, Michel SLJ. Classical Cys2His2 Zinc Finger Peptides Are Rapidly Oxidized by Either H2O2 or O2 Irrespective of Metal Coordination. Inorg Chem 2011; 50:5442-50. [DOI: 10.1021/ic102252a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Seung Jae Lee
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201-1180, United States
| | - Jamie L. Michalek
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201-1180, United States
| | - Angelique N. Besold
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201-1180, United States
| | - Steven E. Rokita
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742-4454, United States
| | - Sarah L. J. Michel
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201-1180, United States
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31
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Morleo A, Bonomi F, Iametti S, Huang VW, Kurtz DM. Iron-nucleated folding of a metalloprotein in high urea: resolution of metal binding and protein folding events. Biochemistry 2010; 49:6627-34. [PMID: 20614892 DOI: 10.1021/bi100630t] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Addition of iron salts to chaotrope-denatured aporubredoxin (apoRd) leads to nearly quantitative recovery of its single Fe(SCys)(4) site and native protein structure without significant dilution of the chaotrope. This "high-chaotrope" approach was used to examine iron binding and protein folding events using stopped-flow UV-vis absorption and CD spectroscopies. With a 100-fold molar excess of ferrous iron over denatured apoRd maintained in 5 M urea, the folded holoFe(III)Rd structure was recovered in >90% yield with a t(1/2) of <10 ms. More modest excesses of iron also gave nearly quantitative holoRd formation in 5 M urea but with chronological resolution of iron binding and protein folding events. The results indicate structural recovery in 5 M urea consists of the minimal sequence: (1) binding of ferrous iron to the unfolded apoRd, (2) rapid formation of a near-native ferrous Fe(SCys)(4) site within a protein having no detectable secondary structure, and (3) recovery of the ferrous Fe(SCys)(4) site chiral environment nearly concomitantly with (4) recovery of the native protein secondary structure. The rate of step 2 (and, by inference, step 1) was not saturated even at a 100-fold molar excess of iron. Analogous results obtained for Cys --> Ser iron ligand variants support formation of an unfolded-Fe(SCys)(3) complex between steps 1 and 2, which we propose is the key nucleation event that pulls together distal regions of the protein chain. These results show that folding of chaotrope-denatured apoRd is iron-nucleated and driven by extraordinarily rapid formation of the Fe(SCys)(4) site from an essentially random coil apoprotein. This high-chaotrope, multispectroscopy approach could clarify folding pathways of other [M(SCys)(3)]- or [M(SCys)(4)]-containing proteins.
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Affiliation(s)
- Anna Morleo
- DISMA, University of Milan, Via G. Celoria 2, 20133 Milan, Italy
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32
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Besold AN, Lee SJ, Michel SLJ, Lue Sue N, Cymet HJ. Functional characterization of iron-substituted neural zinc finger factor 1: metal and DNA binding. J Biol Inorg Chem 2010; 15:583-90. [DOI: 10.1007/s00775-010-0626-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Accepted: 01/20/2010] [Indexed: 10/19/2022]
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33
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Lin IJ, Xia B, King DS, Machonkin TE, Westler WM, Markley JL. Hyperfine-shifted (13)C and (15)N NMR signals from Clostridium pasteurianum rubredoxin: extensive assignments and quantum chemical verification. J Am Chem Soc 2010; 131:15555-63. [PMID: 19799419 PMCID: PMC2766250 DOI: 10.1021/ja905928x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Stable isotope-labeling methods, coupled with novel techniques for detecting fast-relaxing NMR signals, now permit detailed investigations of paramagnetic centers of metalloproteins. We have utilized these advances to carry out comprehensive assignments of the hyperfine-shifted 13C and 15N signals of the rubredoxin from Clostridium pasteurianum (CpRd) in both its oxidized and reduced states. We used residue-specific labeling (by chemical synthesis) and residue-type-selective labeling (by biosynthesis) to assign signals detected by one-dimensional 15N NMR spectroscopy, to nitrogen atoms near the iron center. We refined and extended these 15N assignments to the adjacent carbonyl carbons by means of one-dimensional 13C[15N] decoupling difference experiments. We collected paramagnetic-optimized SuperWEFT 13C[13C] constant time COSY (SW-CT-COSY) data to complete the assignment of 13C signals of reduced CpRd. By following these 13C signals as the protein was gradually oxidized, we transferred these assignments to carbons in the oxidized state. We have compared these assignments with hyperfine chemical shifts calculated from available X-ray structures of CpRd in its oxidized and reduced forms. The results allow the evaluation of the X-ray structural models as representative of the solution structure of the protein, and they provide a framework for future investigation of the active site of this protein. The methods developed here should be applicable to other proteins that contain a paramagnetic center with high spin and slow electron exchange.
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Affiliation(s)
- I-Jin Lin
- Graduate Program in Biophysics, University of Wisconsin-Madison, 433 Babcock Drive, Madison, Wisconsin 53706, USA
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Radian A, Michaeli D, Serban C, Nechushtai R, Mishael YG. Bioactive apo-ferredoxin–polycation–clay composites for iron binding. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/c0jm00232a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Maganas D, Milikisyants S, Rijnbeek JMA, Sottini S, Levesanos N, Kyritsis P, Groenen EJJ. A Multifrequency High-Field Electron Paramagnetic Resonance Study of CoIIS4 Coordination. Inorg Chem 2009; 49:595-605. [DOI: 10.1021/ic901911h] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dimitrios Maganas
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, GR-15771 Athens, Greece
| | - Sergey Milikisyants
- Department of Molecular Physics, Huygens Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
| | - Jorrit M. A. Rijnbeek
- Department of Molecular Physics, Huygens Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
| | - Silvia Sottini
- Department of Molecular Physics, Huygens Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
| | - Nikolaos Levesanos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, GR-15771 Athens, Greece
| | - Panayotis Kyritsis
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, GR-15771 Athens, Greece
| | - Edgar J. J. Groenen
- Department of Molecular Physics, Huygens Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden, The Netherlands
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36
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Łuczkowski M, Stachura M, Schirf V, Demeler B, Hemmingsen L, Pecoraro VL. Design of thiolate rich metal binding sites within a peptidic framework. Inorg Chem 2009; 47:10875-88. [PMID: 18959366 DOI: 10.1021/ic8009817] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A de novo protein design strategy provides a powerful tool to elucidate how heavy metals interact with proteins.Cysteine derivatives of the TRI peptide family (Ac-G(LKALEEK)4G-NH2) have been shown to bind heavy metals in an unusual trigonal geometry. Our present objective was to design binding sites in R-helical scaffolds that are able to form higher coordination number complexes with Cd(II) and Hg(II). Herein, we evaluate the binding of Cd(II) and Hg(II) to double cysteine substituted TRI peptides lacking intervening leucines between sulfurs in the heptads. We compare a -Cysd-X-X-X-Cysa- binding motif found in TRIL12CL16C to the more common -Cysa-X-X-Cysd- sequence of native proteins found in TRIL9CL12C. Compared to TRI, these substitutions destabilize the helical aggregates,leading to mixtures of two- and three-stranded bundles. The three-stranded coiled coils are stabilized by the addition of metals. TRIL9CL12C forms distorted tetrahedral complexes with both Cd(II) and Hg(II), as supported by UV-vis,CD, 113Cd NMR, 199Hg NMR and 111mCd PAC spectroscopy. Additionally, these signatures are very similar to those found for heavy metal substituted rubredoxin. These results suggest that in terms of Hg(II) binding, TRIL9CL12Ccan be considered as a good mimic of the metallochaperone HAH1, that has previously been shown to form protein dimers. TRIL12CL16C has limited ability to generate homoleptic tetrahedral complexes (Cd(SR)42-). These type of complexes were identified only for Hg(II). However, the spectroscopic signatures suggest a different geometry around the metal ion, demonstrating that effective metal sequestration into the hydrophobic interior of the bundle requires more than simply adding two sulfur residues in adjacent layers of the peptide core. Thus, proper design of metal binding sites must also consider the orientation of cysteine sidechains in a vs d positions of the heptads.
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Affiliation(s)
- Marek Łuczkowski
- Department of Chemistry, UniVersity of Michigan, Ann Arbor, Michigan 48109-1055, USA
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37
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Battin EE, Brumaghim JL. Metal specificity in DNA damage prevention by sulfur antioxidants. J Inorg Biochem 2008; 102:2036-42. [DOI: 10.1016/j.jinorgbio.2008.06.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Revised: 06/04/2008] [Accepted: 06/14/2008] [Indexed: 01/30/2023]
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38
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Mukherjee M, Zhu X, Ogawa MY. Cd2+-Induced Conformational Change of a Synthetic Metallopeptide: Slow Metal Binding Followed by a Slower Conformational Change. Inorg Chem 2008; 47:4430-2. [DOI: 10.1021/ic702370k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Madhumita Mukherjee
- Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403
| | - Xianchun Zhu
- Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403
| | - Michael Y. Ogawa
- Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403
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39
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Badarau A, Firbank SJ, Waldron KJ, Yanagisawa S, Robinson NJ, Banfield MJ, Dennison C. FutA2 is a ferric binding protein from Synechocystis PCC 6803. J Biol Chem 2008; 283:12520-7. [PMID: 18252722 DOI: 10.1074/jbc.m709907200] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Synechocystis PCC 6803 has a high demand for iron (10 times greater than Escherichia coli) to sustain photosynthesis and is unusual in possessing at least two putative iron-binding proteins of a type normally associated with ATP-binding cassette-type importers. It has been suggested that one of these, FutA2, binds ferrous iron, but herein we clearly demonstrate that this protein avidly binds Fe(III), the oxidation state preference of periplasmic iron-binding proteins. Structures of apo-FutA2 and Fe-FutA2 have been determined at 1.7 and 2.7A, respectively. The metal ion is bound in a distorted trigonal bipyramidal arrangement with no exogenous anions as ligands. The metal-binding environment, including the second coordination sphere and charge properties, is consistent with a preference for Fe(III). Atypically, FutA2 has a Tat signal peptide, and its inability to coordinate divalent cations may be crucial to prevent metals from binding to the folded protein prior to export from the cytosol. A loop containing the His(43) ligand undergoes considerable movement in apo-versus Fe-FutA2 and may control metal release to the importer. Although these data are consistent with FutA2 being the periplasmic component involved in iron uptake, deletion of another putative ferric binding protein, FutA1, has a greater effect on the accumulation of iron and is more analogous to a DeltafutA1DeltafutA2 double mutant than DeltafutA2. Here, we also discover that there is a reduced level of ferric FutA2 in the periplasm of the DeltafutA1 mutant providing an explanation for its severe iron-uptake phenotype.
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Affiliation(s)
- Adriana Badarau
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
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40
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Maglio O, Nastri F, Martin de Rosales RT, Faiella M, Pavone V, DeGrado WF, Lombardi A. Diiron-containing metalloproteins: Developing functional models. CR CHIM 2007. [DOI: 10.1016/j.crci.2007.03.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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41
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Abstract
Herein, we describe the design and surface-binding characterization of a de novo designed peptide, JAK1, which undergoes surface-induced folding at the hydroxyapatite (HA)-solution interface. JAK1 is designed to be unstructured in buffered saline solution, yet undergo HA-induced folding that is largely governed by the periodic positioning of gamma-carboxyglutamic acid (Gla) residues within the primary sequence of the peptide. Circular dichroism (CD) spectroscopy and analytical ultracentrifugation indicate that the peptide remains unfolded and monomeric in solution under normal physiological conditions; however, CD spectroscopy indicates that in the presence of hydroxyapatite, the peptide avidly binds to the mineral surface adopting a helical structure. Adsorption isotherms indicate nearly quantitative surface coverage and Kd = 310 nM for the peptide-surface binding event. X-ray photoelectron spectroscopy (XPS) coupled with the adsorption isotherm data suggests that JAK1 binds to HA, forming a self-limiting monolayer. This study demonstrates the feasibility of using HA surfaces to trigger the intramolecular folding of designed peptides and represents the initial stages of defining the design rules that allow HA-induced peptide folding.
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Affiliation(s)
- Lisa A Capriotti
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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42
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Spiegel K, De Grado WF, Klein ML. Structural and dynamical properties of manganese catalase and the synthetic protein DF1 and their implication for reactivity from classical molecular dynamics calculations. Proteins 2006; 65:317-30. [PMID: 16917908 DOI: 10.1002/prot.21113] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
There is a pressing need for accurate force fields to assist in metalloprotein analysis and design. Recent work on the design of mimics of dimetal proteins highlights the requirements for activity. DF1 is a de novo designed protein, which mimics the overall fold and active site geometry of a series of diiron and dimanganese proteins. Specifically, the dimanganese form of DF1 is a mimic of the natural enzyme manganese catalase, which catalyzes the dismutation reaction of hydrogen peroxide into water and oxygen. During catalytic turnover, the active site has to accommodate both the reduced and the oxidized state of the dimanganese core. The biomimetic protein DF1 is only stable in the reduced form and thus not active. Furthermore, the synthetic protein features an additional bridging glutamate sidechain, which occupies the substrate binding site. The goal of this study is to develop classical force fields appropriate for design of such important dimanganese proteins. To this aim, we use a nonbonded model to represent the metal-ligand interactions, which implicitly takes into account charge transfer and local polarization effects between the metal and its ligands. To calibrate this approach, we compare and contrast geometric and dynamical properties of manganese catalase and DF1. Having demonstrated a good correspondence with experimental structural data, we examine the effect of mutating the bridging glutamate to aspartate (M1) and serine (M2). Classical MD based on the refined forcefield shows that these point mutations affect not only the immediate coordination sphere of the manganese ions, but also the relative position of the helices, improving the similarity to Mn-catalase, especially in case of M2. On the basis of these findings, classical molecular dynamics calculations with the active site parameterization scheme introduced herein seem to be a promising addition to the protein design toolbox.
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Affiliation(s)
- Katrin Spiegel
- Center for Molecular Modeling and Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA.
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43
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ATCUN-like metal-binding motifs in proteins: identification and characterization by crystal structure and sequence analysis. Proteins 2006; 58:211-21. [PMID: 15508143 DOI: 10.1002/prot.20265] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The amino terminal Cu(II)- and Ni(II)-binding (ATCUN) motif is a small metal-binding site found in the N-terminus of many naturally occurring proteins. The ATCUN motif has been implicated in DNA cleavage and has been shown to have antitumor activity. In proteins, the ATCUN motif is formed from a histidine in the third position, its preceding residue and the free N-terminus. Four nitrogen atoms from these three residues act as metal ligands. Knowledge of metal-binding geometry helps in the design of metal-binding peptides and in understanding of the mechanisms of metal-mediated functions. Since the N-terminus region of ATCUN-containing proteins is highly disordered, no geometrical features can be derived from the protein structures. However, the crystal structure of a small metal-bound ATCUN peptide shows that the nitrogen ligands form a distorted square planar geometry. Distance constraints derived from this designed peptide were used to search 1949 polypeptide chains to find ATCUN-like motifs in any position along the polypeptide chain. Only approximately 1.9% and approximately 0.3% of histidines are involved in partial and full ATCUN-like geometric features, respectively. These two datasets were compared with the dataset of all histidines. None of the ATCUN-like motifs occur in the middle of an alpha-helix or a beta-strand. Further sequence analysis revealed total conservation of ATCUN histidines in four proteins including the transcription factor TBX3, implicated in Ulnar-Mammary Syndrome. Our analysis suggests that the ATCUN-like motif in TBX3 is a potential metal-binding site, although a structural role was not completely ruled out. Metal-binding activity in TBX3, if confirmed, will help us to understand the role of metals in transcriptional regulation and is likely to cast light on the causes of some serious genetic disorders. A conformational role is suggested for ATCUN-like motifs in other proteins.
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44
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Maganas D, Staniland SS, Grigoropoulos A, White F, Parsons S, Robertson N, Kyritsis P, Pneumatikakis G. Structural, spectroscopic and magnetic properties of M[R2P(E)NP(E)R′2]2complexes, M = Co, Mn, E = S, Se and R, R′ = Ph oriPr. Covalency of M–S bonds from experimental data and theoretical calculations. Dalton Trans 2006:2301-15. [PMID: 16688318 DOI: 10.1039/b517938f] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The S/Se-containing bidentate ligands LH of the type R2P(E)NHP(E)R'2, E = S, Se and R, R' = Ph or iPr have been employed to synthesize ML2 (M = Mn, Co) complexes which contain the biologically important MS4 core. Theoretical calculations on the LH and L- forms of the ligands probe the geometric and electronic changes induced by the deprotonation of the LH form, which are correlated with structural data from X-ray crystallography. These results reflect the flexibility of the ligands, which enables them to be rather versatile with respect to the formation of ML2 complexes with varied geometries and MEPNPE metallacycle conformations. A series of old and new ML2 complexes have been synthesized and their structural, spectroscopic and magnetic properties characterized in detail. The nephelauxetic ratio beta of the CoL2 complexes provides evidence of covalent interactions, whereas the EPR properties of the MnL2 complexes are interpreted on the basis of predominant ionic interactions, between the metal center and the ligands, respectively. Additional evidence for the existence of covalent interactions in the CoL2 complexes (R = Ph, iPr, or mixed Ph/iPr), is offered by comparisons between their 31P NMR. The aforementioned notations are supported by extensive theoretical calculations on the ML2 (E = S, R = Me) modelled structures, which probe the covalent and ionic character of the M-S bonds when M = Co or Mn. Wider implications of the findings of the present study on the M-S covalency and its importance in the active sites of various metalloenzymes are also discussed.
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Affiliation(s)
- Dimitrios Maganas
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimiopolis, GR-157 71 Athens, Greece
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45
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Kharenko OA, Ogawa MY. Metal-induced folding of a designed metalloprotein. J Inorg Biochem 2005; 98:1971-4. [PMID: 15522423 DOI: 10.1016/j.jinorgbio.2004.07.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Revised: 07/29/2004] [Accepted: 07/30/2004] [Indexed: 10/26/2022]
Abstract
The metal-induced assembly of a designed peptide-based rubredoxin model is described. The C16C19-GGY peptide has the sequence Ac-K(IEALEGK)(2)(CEACEGK)(IEALEGK)GGY-amide in which the presence of the Cys-X-X-Cys metal binding domain of rubredoxin was used to place cysteine residues at the hydrophobic "a" and "d" positions upon formation of a homodimeric alpha-helical coiled-coil. Circular dichroism spectroscopy shows that the apopeptide exists as a random coil and assembles into a coiled-coil in the presence of Cd(2+). Metal binding is monitored by the appearance of a new LMCT band at 238 nm. UV-Vis titrations and SDS-PAGE experiments are used to show that this designed metalloprotein exists as a metal-bridged coiled-coil dimer.
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Affiliation(s)
- Olesya A Kharenko
- Department of Chemistry, Center for Photochemical Sciences, Bowling Green State University, 141 Overman, Bowling Green, OH 43403, USA
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46
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Kou W, Kolla HS, Ortiz-Acevedo A, Haines DC, Junker M, Dieckmann GR. Modulation of zinc- and cobalt-binding affinities through changes in the stability of the zinc ribbon protein L36. J Biol Inorg Chem 2005; 10:167-80. [PMID: 15747135 DOI: 10.1007/s00775-005-0625-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Accepted: 01/13/2005] [Indexed: 10/25/2022]
Abstract
Cysteine-rich Zn(II)-binding sites in proteins serve two distinct functions: to template or stabilize specific protein folds, and to facilitate chemical reactions such as alkyl transfers. We are interested how the protein environment controls metal site properties, specifically, how naturally occurring tetrahedral Zn(II) sites are affected by the surrounding protein. We have studied the Co(II)- and Zn(II)-binding of a series of derivatives of L36, a small zinc ribbon protein containing a (Cys)(3)His metal coordination site. UV-vis spectroscopy was used to monitor metal binding by peptides at pH 6.0. For all derivatives, the following trends were observed: (1) Zn(II) binds tighter than Co(II), with an average K (A) (Zn) /K (A) (Co) of 2.8(+/-2.0)x10(3); (2) mutation of the metal-binding ligand His32 to Cys decreases the affinity of L36 derivatives for both metals; (3) a Tyr24 to Trp mutation in the beta-sheet hydrophobic cluster increases K (A) (Zn) and K (A) (Co) ; (4) mutation in the beta-hairpin turn, His20 to Asn generating an Asn-Gly turn, also increases K (A) (Zn) and K (A) (Co) ; (5) the combination of His20 to Asn and Tyr24 to Trp mutations also increases K (A) (Zn) and K (A) (Co) , but the increments versus C(3)H are less than those of the single mutations. Furthermore, circular dichroism, size-exclusion chromatography, and 1D and 2D (1)H NMR experiments show that the mutations do not change the overall fold or association state of the proteins. L36, displaying Co(II)- and Zn(II)-binding sensitivity to various sequence mutations without undergoing a change in protein structure, can therefore serve as a useful model system for future structure/reactivity studies.
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Affiliation(s)
- Wenpeng Kou
- Department of Chemistry, The University of Texas at Dallas, Richardson, 75083-0688, USA
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47
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Kennedy ML, Petros AK, Gibney BR. Cobalt(II) and zinc(II) binding to a ferredoxin maquette. J Inorg Biochem 2004; 98:727-32. [PMID: 15134918 DOI: 10.1016/j.jinorgbio.2004.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2003] [Revised: 12/30/2003] [Accepted: 01/05/2004] [Indexed: 10/26/2022]
Abstract
We have examined the Co(II) and Zn(II) affinity of the prototype ferredoxin maquette ligand, NH(2)-KLCEGG.CIACGAC.GGW-CONH2 (IAA), which was originally designed to bind a [4Fe-4S] cluster. UV-Vis spectroscopy demonstrates tight 1:1 complex formation between Co(II) and IAA. The intensity of the S-->Co(II) charge transfer bands at 304 and 340 nm and the ligand field bands between 630 and 728 nm indicate Co(II) coordination by the four cysteine thiolates of IAA in a pseudo-tetrahedral geometry. A dissociation constant value of 5.3 microM was determined for the Co(II)-IAA complex at pH 6.5. Zn(II) readily displaces Co(II) from IAA as evinced by loss of the Co(II) spectral features. The dissociation constant for Zn(II), 20 pM at pH 6.5, was determined be competition experiments with Co(II)-IAA. These results demonstrate that the ferredoxin maquette ligand is an excellent ligand for Zn(II).
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Affiliation(s)
- Michelle L Kennedy
- Department of Chemistry, Columbia University, 3000 Broadway, MC 3121, New York, NY 10027, USA
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48
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Affiliation(s)
- A Lombardi
- Department of Chemistry, University of Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cynthia 45, I-80126 Napoli, Italy.
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49
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Abstract
Recent progress in the rational design of metal sites within peptide model systems shows increasing control in the placement of metals within helical bundles and inclusion of sophisticated elements such as second-sphere ligand interactions. A crystallographically characterized two-metal peptide model for diiron proteins represents a major achievement in de novo design methodologies. Increasingly complex and robust models for electron transfer through and between helices, and electrode-supported electron-transfer peptides, have been constructed. Design elements for peptide-supported ferredoxins and mononuclear Fe(II) and Zn(II) sites have been refined.
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Affiliation(s)
- G Xing
- Department of Chemistry, Texas A&M University, College Station 77842-3012, USA
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50
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HILL RBLAKE, RALEIGH DANIELP, LOMBARDI ANGELA, DEGRADO WILLIAMF. De novo design of helical bundles as models for understanding protein folding and function. Acc Chem Res 2000; 33:745-54. [PMID: 11087311 PMCID: PMC3050006 DOI: 10.1021/ar970004h] [Citation(s) in RCA: 227] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
De novo protein design has proven to be a powerful tool for understanding protein folding, structure, and function. In this Account, we highlight aspects of our research on the design of dimeric, four-helix bundles. Dimeric, four-helix bundles are found throughout nature, and the history of their design in our laboratory illustrates our hierarchic approach to protein design. This approach has been successfully applied to create a completely native-like protein. Structural and mutational analysis allowed us to explore the determinants of native protein structure. These determinants were then applied to the design of a dinuclear metal-binding protein that can now serve as a model for this important class of proteins.
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Affiliation(s)
| | | | | | - WILLIAM F. DEGRADO
- To whom correspondence should be addressed. . Telephone: (215) 898-4590. Fax: (215) 573-7229
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