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Electronic/molecular structure of enzyme heme pockets

酶血红素口袋的电子/分子结构

基本信息

批准号：
7585714
负责人：
GERD N LA MAR
金额：
$ 21.42万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-05-01 至 2011-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7585714
关键词：
Active Sites Address Anisotropy Attention Bacteria Biliverdine Binding C-terminal Chemicals Cleaved cell Comparative Study Complement Complex Coupling Crystallography Cyanides Diphtheria Disease Distal Electronics Enzyme Inhibitor Drugs Enzyme Inhibitors Enzymes Exhibits Goals Heme Hemin Heterogeneity Human Hydrogen Bonding Individual Investigation Iron Ligands Modeling Molecular Molecular Structure Monitor Mutagenesis Nature Oxygenases Pattern Planet Mars Plants Porphyrins Procedures Process Property Protons Reaction Relative (related person)Research Research Personnel Resolution Rest Role Sequence Homology Series Site Solutions Solvents Structure Techniques Vertebrates Water alkalinity base cofactor cryogenics design electronic structure hemin-CN improved interest novel oxidation pathogenic bacteria polypeptide programs response role model tool

项目摘要

We propose the detailed study of functionally relevant molecular/electronic structural and dynamic properties of a series of heme oxygenase, HO, enzymes and their complexes with substrate/reaction intermediates in variable oxidation/spin/liagtion states, using high resolution solution 2D/3D NMR. HO, found in vertebrates, plants and bacteria, acts by a common mechanism and set of intermediates, using heme as both substrate and cofactor, to stereoselectively cleave heme into a-biliverdin, iron and CO. HO is unique in using the hydrpperoxy species as its activated form, and the structural properties of the active site that stabilize the species are not well understood except that ordered water molecules within a distal H-bond network are involved. We select three HOs, ispzyme #1 from human, hHO, and those from two pathogenic bacteria C. diphtheriae (CofHO) and N. meningitidis (NmHO), which share a common fold, but exhibit variable sequence homology for the residues involved in the H-bonding network. The target derivatives are substrate-free or app-HO, resting state HO-hemin-H/jO, HO-hemin-CN as a model for the unstable oxy complex, and HO-hemin-OH as a model for the reactive hydroperpxy species. Since all but one targeted HO derivative are paramagnetic, emphasis is placed on utilizing appropriately tailored 1D/2D/3D NMR to extract the wealth of unique information in hyperfine shifts. We will develop a new and highly sensitive NMR probe that directly reflect the degree of H-bonding between axial ligand to the hemin and the distal ordered-water/H-bond network, using the pair of complex HO-hemin-H2O/-OH, and to use this probe, as well as previously established procedures, to provide a detailed characterization of the solution structure. Our interests focus on comparison of local solution with cryogenic crystallographic molecular structure, with particular attention paid to extended H-bond networks with some remarkably robust H-bonds, and the ordered water molecules within these networks. We emphasize comparative studies among the various derivatives of one HO, and among the different HOs for a given derivative, to elucidate the relationship between variable strength H-bonds and axial ligand properties. In addition, we will characterize the influence of HO, substrate or intermediates and their axial ligands on dynamic properties related to entry and exit of substrate. Lastly, for NmHO, we will characterize the influence of heme substituents on its seating in the active site, determine the structure of the crystallographically disordered C-terminus found folded into the active site in solution, and illuminate the role of the C-terminus and the unique active site Cys113 in multiple, functionally relevant, microheterogeneities. The detailed description of the molecular structural and dynamic properties of heme oxygenase will improve our understanding of the varied roles of mammalian enzymes. The elucidation of the similarities and differences between bacterial and mammalian heme oxygenase will improve prospects for the design of selective inhibitors for the enzyme in pathogenic bacteria.

我们建议详细研究功能相关的分子/电子结构和动力学

项目成果

期刊论文数量（20）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

1H NMR study of the influence of mutation on the interaction of the C-terminus with the active site in heme oxygenase from Neisseria meningitidis: implications for product release.

1H NMR 研究突变对脑膜炎奈瑟菌血红素加氧酶 C 末端与活性位点相互作用的影响：对产品释放的影响。

DOI：
10.1021/bi1000867
发表时间：
2010
期刊：
Biochemistry
影响因子：
2.9
作者：
Peng,Dungeng;Ma,Li-Hua;Ogura,Hiroshi;Yang,En-Che;Zhang,Xuhong;Yoshida,Tadashi;LaMar,GerdN
通讯作者：
LaMar,GerdN

Influence of substrate modification and C-terminal truncation on the active site structure of substrate-bound heme oxygenase from Neisseriae meningitidis. A 1H NMR study.

DOI：
10.1021/bi200978g
发表时间：
2011-10-18
期刊：
BIOCHEMISTRY
影响因子：
2.9
作者：
Peng, Dungeng;Satterlee, James D.;Ma, Li-Hua;Dallas, Jerry L.;Smith, Kevin M.;Zhang, Xuhong;Sato, Michihiko;La Mar, Gerd N.
通讯作者：
La Mar, Gerd N.

1H NMR detection of immobilized water molecules within a strong distal hydrogen-bonding network of substrate-bound human heme oxygenase-1.