Abstract

We propose to utilize pulsed EPR methods to study the structure and function of the tetranuclear Mn cluster of Photosystem II (PS II) of plant photosynthesis and the Mn catalase enzyme. Specifically, the techniques of electron spin echo envelope modulation (ESEEM) and electron spin echo - electron nuclear double resonance (ESE-ENDOR) will be utilized to detect nuclear spin transitions of magnetic nuclei within and in close proximity to these multinuclear Mn clusters. High frequency ESE-ENDOR will be utilized to measure the 55Mn spin transitions of the biological Mn clusters and of synthetic model compounds of known structure. Oriented PS ll membranes and single crystals of PS ll will be studied for enhanced resolution. These experiments will provide new knowledge about the structure of this essential catalytic site. The protein ligation to the Mn clusters in PS H and catalase will be explored. The binding of substrate and inhibitor molecules will be characterized. For the PS ll Mn cluster, experiments will be per- formed to characterize the roles of Ca2+ and Cl-, which are essential cofactors in the oxygen evolution chemistry. Experiments will be performed to test the hypothesis that photosynthetic oxygen evolution occurs with a metalloradical mechanism, involving both the Mn cluster and tyrosine Yz. Parallel polarization EPR signals will be used to detect integer spin signals of the Mn clusters.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM048242-08
Application #
6018925
Study Section
Metallobiochemistry Study Section (BMT)
Project Start
1992-07-01
Project End
2001-06-30
Budget Start
1999-07-01
Budget End
2000-06-30
Support Year
8
Fiscal Year
1999
Total Cost
Indirect Cost

  Institution

Name
University of California Davis
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618

  Publications

Ragsdale, Stephen W; Yi, Li; Bender, Güne? et al. (2012) Redox, haem and CO in enzymatic catalysis and regulation. Biochem Soc Trans 40:501-7
Sheng, Yuewei; Stich, Troy A; Barnese, Kevin et al. (2011) Comparison of two yeast MnSODs: mitochondrial Saccharomyces cerevisiae versus cytosolic Candida albicans. J Am Chem Soc 133:20878-89
Stich, Troy A; Yeagle, Gregory J; Service, Rachel J et al. (2011) Ligation of D1-His332 and D1-Asp170 to the manganese cluster of photosystem II from Synechocystis assessed by multifrequency pulse EPR spectroscopy. Biochemistry 50:7390-404
Dicus, Michelle M; Conlan, Andrea; Nechushtai, Rachel et al. (2010) Binding of histidine in the (Cys)3(His)1-coordinated [2Fe-2S] cluster of human mitoNEET. J Am Chem Soc 132:2037-49
Ellis, Paul D; Sears, Jesse A; Yang, Ping et al. (2010) Solid-state (55)Mn NMR spectroscopy of bis(ýý-oxo)dimanganese(IV) [Mn(2)O(2)(salpn)(2)], a model for the oxygen evolving complex in photosystem II. J Am Chem Soc 132:16727-9
Bender, Güne?; Stich, Troy A; Yan, Lifen et al. (2010) Infrared and EPR spectroscopic characterization of a Ni(I) species formed by photolysis of a catalytically competent Ni(I)-CO intermediate in the acetyl-CoA synthase reaction. Biochemistry 49:7516-23
Barnese, Kevin; Sheng, Yuewei; Stich, Troy A et al. (2010) Investigation of the highly active manganese superoxide dismutase from Saccharomyces cerevisiae. J Am Chem Soc 132:12525-7
Stich, Troy A; Whittaker, James W; Britt, R David (2010) Multifrequency EPR studies of manganese catalases provide a complete description of proteinaceous nitrogen coordination. J Phys Chem B 114:14178-88
Stull, Jamie A; Stich, Troy A; Service, Rachel J et al. (2010) 13C ENDOR reveals that the D1 polypeptide C-terminus is directly bound to Mn in the photosystem II oxygen evolving complex. J Am Chem Soc 132:446-7
Stoll, Stefan; Britt, R David (2009) General and efficient simulation of pulse EPR spectra. Phys Chem Chem Phys 11:6614-25

Showing the most recent 10 out of 12 publications