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Designing minimalist membrane proteins. Biochem Soc Trans 2020; 47:1233-1245. [PMID: 31671181 PMCID: PMC6824673 DOI: 10.1042/bst20190170] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/05/2019] [Accepted: 08/12/2019] [Indexed: 12/13/2022]
Abstract
The construction of artificial membrane proteins from first principles is of fundamental interest and holds considerable promise for new biotechnologies. This review considers the potential advantages of adopting a strictly minimalist approach to the process of membrane protein design. As well as the practical benefits of miniaturisation and simplicity for understanding sequence-structure-function relationships, minimalism should also support the abstract conceptualisation of membrane proteins as modular components for synthetic biology. These ideas are illustrated with selected examples that focus upon α-helical membrane proteins, and which demonstrate how such minimalist membrane proteins might be integrated into living biosystems.
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2
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Grayson KJ, Anderson JLR. Designed for life: biocompatible de novo designed proteins and components. J R Soc Interface 2019; 15:rsif.2018.0472. [PMID: 30158186 PMCID: PMC6127164 DOI: 10.1098/rsif.2018.0472] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 08/01/2018] [Indexed: 12/30/2022] Open
Abstract
A principal goal of synthetic biology is the de novo design or redesign of biomolecular components. In addition to revealing fundamentally important information regarding natural biomolecular engineering and biochemistry, functional building blocks will ultimately be provided for applications including the manufacture of valuable products and therapeutics. To fully realize this ambitious goal, the designed components must be biocompatible, working in concert with natural biochemical processes and pathways, while not adversely affecting cellular function. For example, de novo protein design has provided us with a wide repertoire of structures and functions, including those that can be assembled and function in vivo. Here we discuss such biocompatible designs, as well as others that have the potential to become biocompatible, including non-protein molecules, and routes to achieving full biological integration.
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Affiliation(s)
- Katie J Grayson
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, UK
| | - J L Ross Anderson
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, UK .,BrisSynBio Synthetic Biology Research Centre, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
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3
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Goparaju G, Fry BA, Chobot SE, Wiedman G, Moser CC, Leslie Dutton P, Discher BM. First principles design of a core bioenergetic transmembrane electron-transfer protein. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1857:503-512. [PMID: 26672896 PMCID: PMC4846532 DOI: 10.1016/j.bbabio.2015.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 11/14/2015] [Accepted: 12/01/2015] [Indexed: 12/26/2022]
Abstract
Here we describe the design, Escherichia coli expression and characterization of a simplified, adaptable and functionally transparent single chain 4-α-helix transmembrane protein frame that binds multiple heme and light activatable porphyrins. Such man-made cofactor-binding oxidoreductases, designed from first principles with minimal reference to natural protein sequences, are known as maquettes. This design is an adaptable frame aiming to uncover core engineering principles governing bioenergetic transmembrane electron-transfer function and recapitulate protein archetypes proposed to represent the origins of photosynthesis. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.
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Affiliation(s)
- Geetha Goparaju
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bryan A Fry
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sarah E Chobot
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gregory Wiedman
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christopher C Moser
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - P Leslie Dutton
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bohdana M Discher
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA.
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4
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Razeghifard R. Photochemistry of free and bound Zn-chlorophyll analogues to synthetic peptides depend on the quinone and pH. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 152:416-24. [PMID: 26232025 DOI: 10.1016/j.jphotobiol.2015.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 07/18/2015] [Accepted: 07/22/2015] [Indexed: 10/23/2022]
Abstract
A synthetic peptide was used as a scaffold to bind Zn-Chlorophyll (ZnChl) analogues through histidine ligation to study their photochemistry in the presence of different type of quinones. The Chl analogues were chlorin e6 (Ce6), chlorin e6 trimethyl ester, pyropheophorbide a, and pheophorbide a while the quinones were PPBQ, DMBQ, NPHQ, DBTQ, DCBQ and PBQ. The binding of each ZnChl analogue to the peptide was verified by native gel electrophoresis. First the photo-stability of the ZnChl analogues were tested under continuous light. The ZnCe6 and ZnCe6TM analogues showed the least stability judged by the loss of optical signal intensity at their Qy band. The photoactivity of each ZnChl analogue was measured in the presence of each of the six quinones using time-resolved EPR spectroscopy. DMBQ was found to be the most efficient electron acceptor when all four ZnChl analogues were compared. The light-induced electron transfer between the ZnChl analogues complexed with the peptide and DMBQ were also measured using time-resolved EPR spectroscopy. The ZnCe6-peptide complex exhibited the highest photoactivity. The electron transfer in the complex was faster and the photoactivity yield was higher than those values obtained for free ZnCe6 and DMBQ. The fast phase of kinetics can be attributed to intra-protein electron transfer in the complex since it was not observed in the presence of DMBQ-glutathione adduct. Unlike free ZnCe6, the ZnCe6-peptide complex was robust and demonstrated very similar photoactivity efficiency in pH values 10, 8.0 and 5.0. The electron transfer kinetics were pH dependent and appeared to be modulated by the peptide charge and possibly fold. The charge recombination rate was slowed by an order of magnitude when the pH value was changed from 10.0 to 5.0. The implications of constructing the photoactive peptide complexes in terms of artificial photosynthesis are discussed.
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Affiliation(s)
- Reza Razeghifard
- Department of Chemistry and Physics, Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, Fort Lauderdale, FL 33314, United States.
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5
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Mahajan M, Bhattacharjya S. Designed di-heme binding helical transmembrane protein. Chembiochem 2014; 15:1257-62. [PMID: 24829076 DOI: 10.1002/cbic.201402142] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Indexed: 01/03/2023]
Abstract
De novo designing of functional membrane proteins is fundamental in terms of understanding the structure, folding, and stability of membrane proteins. In this work, we report the design and characterization of a transmembrane protein, termed HETPRO (HEme-binding Transmembrane PROtein), that binds two molecules of heme in a membrane and catalyzes oxidation/reduction reactions. The primary structure of HETPRO has been optimized in a guided fashion, from an antimicrobial peptide, for transmembrane orientation, defined 3D structure, and functions. HETPRO assembles into a tetrameric form, from an apo dimeric helical structure, in complex with cofactor in detergent micelles. The NMR structure of the apo HETPRO in micelles reveals an antiparallel helical dimer that inserts into the nonpolar core of detergent micelles. The well-defined structure of HETPRO and its ability to bind to heme moieties could be utilized to develop a functional membrane protein mimic for electron transport and photosystems.
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Affiliation(s)
- Mukesh Mahajan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore-637551 (Singapore)
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6
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Watkins DW, Armstrong CT, Anderson JLR. De novo protein components for oxidoreductase assembly and biological integration. Curr Opin Chem Biol 2014; 19:90-8. [DOI: 10.1016/j.cbpa.2014.01.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/23/2014] [Accepted: 01/29/2014] [Indexed: 01/03/2023]
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7
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Mahajan M, Bhattacharjya S. β-Hairpin peptides: heme binding, catalysis, and structure in detergent micelles. Angew Chem Int Ed Engl 2013; 52:6430-4. [PMID: 23640811 DOI: 10.1002/anie.201300241] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 03/25/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Mukesh Mahajan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
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8
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Mahajan M, Bhattacharjya S. β-Hairpin Peptides: Heme Binding, Catalysis, and Structure in Detergent Micelles. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201300241] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
The last two decades have led to significant progress in the field of analytical ultracentrifugation driven by instrumental, theoretical, and computational methods. This review will highlight key developments in sedimentation equilibrium (SE) and sedimentation velocity (SV) analysis. For SE, this includes the analysis of tracer sedimentation equilibrium at high concentrations with strong thermodynamic non-ideality, and for ideally interacting systems the development of strategies for the analysis of heterogeneous interactions towards global multi-signal and multi-speed SE analysis with implicit mass conservation. For SV, this includes the development and applications of numerical solutions of the Lamm equation, noise decomposition techniques enabling direct boundary fitting, diffusion deconvoluted sedimentation coefficient distributions, and multi-signal sedimentation coefficient distributions. Recently, effective particle theory has uncovered simple physical rules for the co-migration of rapidly exchanging systems of interacting components in SV. This has opened new possibilities for the robust interpretation of the boundary patterns of heterogeneous interacting systems. Together, these SE and SV techniques have led to new approaches to study macromolecular interactions across the entire the spectrum of affinities, including both attractive and repulsive interactions, in both dilute and highly concentrated solutions, which can be applied to single-component solutions of self-associating proteins as well as the study of multi-protein complex formation in multi-component solutions.
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Affiliation(s)
- Peter Schuck
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, U.S.A
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10
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Aravindu K, Mass O, Vairaprakash P, Springer JW, Yang E, Niedzwiedzki DM, Kirmaier C, Bocian DF, Holten D, Lindsey JS. Amphiphilic chlorins and bacteriochlorins in micellar environments. Molecular design, de novo synthesis, and photophysical properties. Chem Sci 2013. [DOI: 10.1039/c3sc51335a] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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11
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Kathan-Galipeau K, Nanayakkara S, O'Brian PA, Nikiforov M, Discher BM, Bonnell DA. Direct probe of molecular polarization in de novo protein-electrode interfaces. ACS NANO 2011; 5:4835-4842. [PMID: 21612231 DOI: 10.1021/nn200887n] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A novel approach to energy harvesting and biosensing devices would exploit optoelectronic processes found in proteins that occur in nature. However, in order to design such systems, the proteins need to be attached to electrodes and the optoelectronic properties in nonliquid (ambient) environments must be understood at a fundamental level. Here we report the simultaneous detection of electron transport and the effect of optical absorption on dielectric polarizability in oriented peptide single molecular layers. This characterization requires a peptide design strategy to control protein/electrode interface interactions, to allow peptide patterning on a substrate, and to induce optical activity. In addition, a new method to probe electronic, dielectric, and optical properties at the single molecular layer level is demonstrated. The combination enables a quantitative comparison of the change in polarization volume between the ground state and excited state in a single molecular layer in a manner that allows spatial mapping relevant to ultimate device design.
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Affiliation(s)
- Kendra Kathan-Galipeau
- Department of Materials Science and Biophysics, The University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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12
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Cohen-Ofri I, van Gastel M, Grzyb J, Brandis A, Pinkas I, Lubitz W, Noy D. Zinc-Bacteriochlorophyllide Dimers in de Novo Designed Four-Helix Bundle Proteins. A Model System for Natural Light Energy Harvesting and Dissipation. J Am Chem Soc 2011; 133:9526-35. [DOI: 10.1021/ja202054m] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ilit Cohen-Ofri
- Plant Sciences Department, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Maurice van Gastel
- Max Planck Institute for Bioinorganic Chemistry, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Joanna Grzyb
- Plant Sciences Department, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alexander Brandis
- Plant Sciences Department, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Iddo Pinkas
- Plant Sciences Department, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Wolfgang Lubitz
- Max Planck Institute for Bioinorganic Chemistry, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Dror Noy
- Plant Sciences Department, Weizmann Institute of Science, Rehovot 76100, Israel
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13
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Korendovych IV, Senes A, Kim YH, Lear JD, Fry HC, Therien MJ, Blasie JK, Walker FA, Degrado WF. De novo design and molecular assembly of a transmembrane diporphyrin-binding protein complex. J Am Chem Soc 2011; 132:15516-8. [PMID: 20945900 DOI: 10.1021/ja107487b] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The de novo design of membrane proteins remains difficult despite recent advances in understanding the factors that drive membrane protein folding and association. We have designed a membrane protein PRIME (PoRphyrins In MEmbrane) that positions two non-natural iron diphenylporphyrins (Fe(III)DPP's) sufficiently close to provide a multicentered pathway for transmembrane electron transfer. Computational methods previously used for the design of multiporphyrin water-soluble helical proteins were extended to this membrane target. Four helices were arranged in a D(2)-symmetrical bundle to bind two Fe(II/III) diphenylporphyrins in a bis-His geometry further stabilized by second-shell hydrogen bonds. UV-vis absorbance, CD spectroscopy, analytical ultracentrifugation, redox potentiometry, and EPR demonstrate that PRIME binds the cofactor with high affinity and specificity in the expected geometry.
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Affiliation(s)
- Ivan V Korendovych
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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14
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Williamson A, Conlan B, Hillier W, Wydrzynski T. The evolution of Photosystem II: insights into the past and future. PHOTOSYNTHESIS RESEARCH 2011; 107:71-86. [PMID: 20512415 DOI: 10.1007/s11120-010-9559-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Accepted: 05/07/2010] [Indexed: 05/29/2023]
Abstract
This article attempts to address the molecular origin of Photosystem II (PSII), the central component in oxygenic photosynthesis. It discusses the possible evolution of the relevant cofactors needed for splitting water into molecular O2 with respect to the following functional domains in PSII: the reaction center (RC), the oxygen evolving complex (OEC), and the manganese stabilizing protein (MSP). Possible ancestral sources of the relevant cofactors are considered, as are scenarios of how these components may have been brought together to produce the intermediate steps in the evolution of PSII. Most importantly, the driving forces that maintained these intermediates for continued adaptation are considered. We then apply our understanding of the evolution of PSII to the bioengineering of a water oxidizing catalyst for utilization of solar energy.
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Affiliation(s)
- Adele Williamson
- Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra, ACT, 0200, Australia
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15
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Kuciauskas D, Kiskis J, Caputo GA, Gulbinas V. Exciton Annihilation and Energy Transfer in Self-Assembled Peptide−Porphyrin Complexes Depends on Peptide Secondary Structure. J Phys Chem B 2010; 114:16029-35. [DOI: 10.1021/jp108685n] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Darius Kuciauskas
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, New Jersey 08108, United States and Institute of Physics, Centre for Physical and Technological Sciences, Savanoriu 238, Vilnius, Lithuania
| | - Juris Kiskis
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, New Jersey 08108, United States and Institute of Physics, Centre for Physical and Technological Sciences, Savanoriu 238, Vilnius, Lithuania
| | - Gregory A. Caputo
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, New Jersey 08108, United States and Institute of Physics, Centre for Physical and Technological Sciences, Savanoriu 238, Vilnius, Lithuania
| | - Vidmantas Gulbinas
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, New Jersey 08108, United States and Institute of Physics, Centre for Physical and Technological Sciences, Savanoriu 238, Vilnius, Lithuania
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16
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Shu JY, Huang YJ, Tan C, Presley AD, Chang J, Xu T. Amphiphilic Peptide−Polymer Conjugates Based on the Coiled-Coil Helix Bundle. Biomacromolecules 2010; 11:1443-52. [DOI: 10.1021/bm100009e] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jessica Y. Shu
- Departments of Materials Science and Engineering and Chemistry, University of California, Berkeley, California 94720, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Yu-Ja Huang
- Departments of Materials Science and Engineering and Chemistry, University of California, Berkeley, California 94720, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Cen Tan
- Departments of Materials Science and Engineering and Chemistry, University of California, Berkeley, California 94720, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Andrew D. Presley
- Departments of Materials Science and Engineering and Chemistry, University of California, Berkeley, California 94720, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Joseph Chang
- Departments of Materials Science and Engineering and Chemistry, University of California, Berkeley, California 94720, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Ting Xu
- Departments of Materials Science and Engineering and Chemistry, University of California, Berkeley, California 94720, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
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Balaban TS, Bhise AD, Bringmann G, Bürck J, Chappaz-Gillot C, Eichhöfer A, Fenske D, Götz DCG, Knauer M, Mizoguchi T, Mössinger D, Rösner H, Roussel C, Schraut M, Tamiaki H, Vanthuyne N. Mimics of the self-assembling chlorosomal bacteriochlorophylls: regio- and stereoselective synthesis and stereoanalysis of acyl(1-hydroxyalkyl)porphyrins. J Am Chem Soc 2009; 131:14480-92. [PMID: 19769331 DOI: 10.1021/ja905628h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Diacylation of copper 10,20-bis(3,5-di-tert-butylphenylporphyrin) using Friedel-Crafts conditions at short reaction times, high concentrations of catalyst, and 0-4 degrees C affords only the 3,17-diacyl-substituted porphyrins, out of the 12 possible regioisomers. At longer reaction times and higher temperatures, the 3,13-diacyl compounds are also formed, and the two isomers can be conveniently separated by normal chromatographic techniques. Monoreduction of these diketones affords in good yields the corresponding acyl(1-hydroxyalkyl)porphyrins, which after zinc metalation are mimics of the natural chlorosomal bacteriochlorophyll (BChl) d. Racemate resolution by HPLC on a variety of chiral columns was achieved and further optimized, thus permitting easy access to enantiopure porphyrins. Enantioselective reductions proved to be less effective in this respect, giving moderate yields and only 79% ee in the best case. The absolute configuration of the 3(1)-stereocenter was assigned by independent chemical and spectroscopic methods. Self-assembly of a variety of these zinc BChl d mimics proves that a collinear arrangement of the hydroxyalkyl substituent with the zinc atom and the carbonyl substituent is not a stringent requirement, since both the 3,13 and the 3,17 regioisomers self-assemble readily as the racemates. Interestingly, the separated enantiomers self-assemble less readily, as judged by absorption, fluorescence, and transmission electron microscopy studies. Circular dichroism spectra of the self-assemblies show intense Cotton effects, which are mirror-images for the two 3(1)-enantiomers, proving that the supramolecular chirality is dependent on the configuration at the 3(1)-stereocenter. Upon disruption of these self-assemblies with methanol, which competes with zinc ligation, only very weak monomeric Cotton effects are present. The favored heterochiral self-assembly process may also be encountered for the natural BChls. This touches upon the long-standing problem of why both 3(1)-epimers are encountered in BChls in ratios that vary with the illumination and culturing conditions.
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Affiliation(s)
- Teodor Silviu Balaban
- Institute for Nanotechnology, Karlsruhe Institute of Technology, Postfach 3640, D-76021 Karlsruhe, Germany.
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18
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Negron C, Fufezan C, Koder RL. Geometric constraints for porphyrin binding in helical protein binding sites. Proteins 2009; 74:400-16. [PMID: 18636480 DOI: 10.1002/prot.22143] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Helical bundles which bind heme and porphyrin cofactors have been popular targets for cofactor-containing de novo protein design. By analyzing a highly nonredundant subset of the protein databank we have determined a rotamer distribution for helical histidines bound to heme cofactors. Analysis of the entire nonredundant database for helical sequence preferences near the ligand histidine demonstrated little preference for amino acid side chain identity, size, or charge. Analysis of the database subdivided by ligand histidine rotamer, however, reveals strong preferences in each case, and computational modeling illuminates the structural basis for some of these findings. The majority of the rotamer distribution matches that predicted by molecular simulation of a single porphyrin-bound histidine residue placed in the center of an all-alanine helix, and the deviations explain two prominent features of natural heme protein binding sites: heme distortion in the case of the cytochromes C in the m166 histidine rotamer, and a highly prevalent glycine residue in the t73 histidine rotamer. These preferences permit derivation of helical consensus sequence templates which predict optimal side chain-cofactor packing interactions for each rotamer. These findings thus promise to guide future design endeavors not only in the creation of higher affinity heme and porphyrin binding sites, but also in the direction of bound cofactor geometry.
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Affiliation(s)
- Christopher Negron
- Department of Physics, the City College of New York, New York, New York 10031, USA
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20
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Conlan B. Designing photosystem II: molecular engineering of photo-catalytic proteins. PHOTOSYNTHESIS RESEARCH 2008; 98:687-700. [PMID: 18777102 DOI: 10.1007/s11120-008-9355-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Accepted: 08/11/2008] [Indexed: 05/26/2023]
Abstract
Biological photosynthesis utilizes membrane-bound pigment/protein complexes to convert light into chemical energy through a series of electron-transfer events. In the unique photosystem II (PSII) complex these electron-transfer events result in the oxidation of water to molecular oxygen. PSII is an extremely complex enzyme and in order to exploit its unique ability to convert sunlight into chemical energy it will be necessary to make a minimal model. Here we will briefly describe how PSII functions and identify those aspects that are essential in order to catalyze the oxidation of water into O(2), and review previous attempts to design simple photo-catalytic proteins and summarize our current research exploiting the E. coli bacterioferritin protein as a scaffold into which multiple cofactors can be bound, to oxidize a manganese metal center upon illumination. Through the reverse engineering of PSII and light driven water splitting reactions it may be possible to provide a blueprint for catalysts that can produce clean green fuel for human energy needs.
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Affiliation(s)
- Brendon Conlan
- Research School of Biological Science, Australian National University, Canberra, ACT 0200, Australia.
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Wydrzynski T, Hillier W, Conlan B. Engineering model proteins for Photosystem II function. PHOTOSYNTHESIS RESEARCH 2007; 94:225-233. [PMID: 17955341 DOI: 10.1007/s11120-007-9271-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Accepted: 10/04/2007] [Indexed: 05/25/2023]
Abstract
Our knowledge of Photosystem II and the molecular mechanism of oxygen production are rapidly advancing. The time is now ripe to exploit this knowledge and use it as a blueprint for the development of light-driven catalysts, ultimately for the splitting of water into O2 and H2. In this article, we outline the background and our approach to this technological application through the reverse engineering of Photosystem II into model proteins.
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Affiliation(s)
- Tom Wydrzynski
- Research School of Biological Sciences, Australian National University, Canberra, ACT, 0200, Australia.
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22
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Blumberger J, Klein ML. Reorganization free energies for long-range electron transfer in a porphyrin-binding four-helix bundle protein. J Am Chem Soc 2007; 128:13854-67. [PMID: 17044714 DOI: 10.1021/ja063852t] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To explore the possibility of electron transport in a recently designed four-helix bundle protein (Cochran, F. V.; et al. J. Am. Chem. Soc. 2005, 127, 1346), we have computed the reorganization free energy for (i) oxidation of a single Ru-porphyrin cofactor and (ii) electron self-exchange between two Ru-porphyrin cofactors binding to the solvated protein. Sampling the classical electrostatic energy gap for 20 ns, we find that the fluctuations are well described by Gaussian statistics and obtain reorganization free energies of 0.90 +/- 0.04 eV for oxidation and 1.36 +/- 0.08 eV for self-exchange. The latter is 0.1-0.2 eV higher than the experimental estimate for interprotein electron self-exchange in cytochrome b5. As in natural electron carriers, inner-sphere reorganization is very small, 88 meV for self-exchange between two model cofactors computed at the density functional level of theory. Decomposing the outer-sphere reorganization free energy, we find that the solvent (aqueous ionic solution) is the primary outer-sphere medium for oxidation, contributing 0.60 eV (69%). The protein contributes only 0.27 eV (31%). For self-exchange, the solvent contribution, 0.68 eV (54%), and the protein contribution, 0.59 eV (46%), are almost equally important. The large solvent contribution is due to the slow decay of dipole reorientation of the solvent as a function of distance to the cofactor, implying that the change in the electric field upon electron transfer is not as effectively screened by the four-helix bundle protein. However, ranking the residues according to their free energy contributions, it is suggested that the reorganization free energy can be decreased by about 0.2 eV if two glutamine residues in the vicinity of the cofactor are mutated into less polar amino acids.
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Affiliation(s)
- Jochen Blumberger
- Center for Molecular Modeling and Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA
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Hong J, Kharenko OA, Ogawa MY. Incorporating electron-transfer functionality into synthetic metalloproteins from the bottom-up. Inorg Chem 2007; 45:9974-84. [PMID: 17140193 PMCID: PMC2566827 DOI: 10.1021/ic060222j] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The alpha-helical coiled-coil motif serves as a robust scaffold for incorporating electron-transfer (ET) functionality into synthetic metalloproteins. These structures consist of a supercoiling of two or more aplha helices that are formed by the self-assembly of individual polypeptide chains whose sequences contain a repeating pattern of hydrophobic and hydrophilic residues. Early work from our group attached abiotic Ru-based redox sites to the most surface-exposed positions of two stranded coiled-coils and used electron-pulse radiolysis to study both intra- and intermolecular ET reactions in these systems. Later work used smaller metallopeptides to investigate the effects of conformational gating within electrostatic peptide-protein complexes. We have recently designed the C16C19-GGY peptide, which contains Cys residues located at both the "a" and "d" positions of its third heptad repeat in order to construct a nativelike metal-binding domain within its hydrophobic core. It was shown that the binding of both Cd(II) and Cu(I) ions induces the peptide to undergo a conformational change from a disordered random coil to a metal-bridged coiled-coil. However, whereas the Cd(II)-protein exists as a two-stranded coiled-coil, the Cu(I) derivative exists as a four-stranded coiled-coil. Upon the incorporation of other metal ions, metal-bridged peptide dimers, tetramers, and hexamers are formed. The Cu(I)-protein is of particular interest because it exhibits a long-lived (microsecond) room-temperature luminescence at 600 nm. The luminophore in this protein is thought to be a multinuclear CuI4Cys4(N/O)4 cage complex, which can be quenched by exogenous electron acceptors in solution, as shown by emission-lifetime and transient-absorption experiments. It is anticipated that further investigation into these systems will contribute to the expanding effort of bioinorganic chemists to prepare new kinds of functionally active synthetic metalloproteins.
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Noy D, Moser CC, Dutton PL. Design and engineering of photosynthetic light-harvesting and electron transfer using length, time, and energy scales. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:90-105. [PMID: 16457774 DOI: 10.1016/j.bbabio.2005.11.010] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2005] [Revised: 11/16/2005] [Accepted: 11/21/2005] [Indexed: 11/20/2022]
Abstract
Decades of research on the physical processes and chemical reaction-pathways in photosynthetic enzymes have resulted in an extensive database of kinetic information. Recently, this database has been augmented by a variety of high and medium resolution crystal structures of key photosynthetic enzymes that now include the two photosystems (PSI and PSII) of oxygenic photosynthetic organisms. Here, we examine the currently available structural and functional information from an engineer's point of view with the long-term goal of reproducing the key features of natural photosystems in de novo designed and custom-built molecular solar energy conversion devices. We find that the basic physics of the transfer processes, namely, the time constraints imposed by the rates of incoming photon flux and the various decay processes allow for a large degree of tolerance in the engineering parameters. Moreover, we find that the requirements to guarantee energy and electron transfer rates that yield high efficiency in natural photosystems are largely met by control of distance between chromophores and redox cofactors. Thus, for projected de novo designed constructions, the control of spatial organization of cofactor molecules within a dense array is initially given priority. Nevertheless, constructions accommodating dense arrays of different cofactors, some well within 1 nm from each other, still presents a significant challenge for protein design.
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Affiliation(s)
- Dror Noy
- Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
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Discher BM, Noy D, Strzalka J, Ye S, Moser CC, Lear JD, Blasie JK, Dutton PL. Design of amphiphilic protein maquettes: controlling assembly, membrane insertion, and cofactor interactions. Biochemistry 2005; 44:12329-43. [PMID: 16156646 PMCID: PMC2574520 DOI: 10.1021/bi050695m] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have designed polypeptides combining selected lipophilic (LP) and hydrophilic (HP) sequences that assemble into amphiphilic (AP) alpha-helical bundles to reproduce key structure characteristics and functional elements of natural membrane proteins. The principal AP maquette (AP1) developed here joins 14 residues of a heme binding sequence from a structured diheme-four-alpha-helical bundle (HP1), with 24 residues of a membrane-spanning LP domain from the natural four-alpha-helical M2 channel of the influenza virus, through a flexible linking sequence (GGNG) to make a 42 amino acid peptide. The individual AP1 helices (without connecting loops) assemble in detergent into four-alpha-helical bundles as observed by analytical ultracentrifugation. The helices are oriented parallel as indicated by interactions typical of adjacent hemes. AP1 orients vectorially at nonpolar-polar interfaces and readily incorporates into phospholipid vesicles with >97% efficiency, although most probably without vectorial bias. Mono- and diheme-AP1 in membranes enhance functional elements well established in related HP analogues. These include strong redox charge coupling of heme with interior glutamates and internal electric field effects eliciting a remarkable 160 mV splitting of the redox potentials of adjacent hemes that leads to differential heme binding affinities. The AP maquette variants, AP2 and AP3, removed heme-ligating histidines from the HP domain and included heme-ligating histidines in LP domains by selecting the b(H) heme binding sequence from the membrane-spanning d-helix of respiratory cytochrome bc(1). These represent the first examples of AP maquettes with heme and bacteriochlorophyll binding sites located within the LP domains.
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Affiliation(s)
- Bohdana M Discher
- Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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