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> | Abstract: DESCRIPTION (provided by applicant): Protein-protein interactions that occur during fertilization will be investigated. Sperm-egg adhesion and fusion is a multi-step process. Two sperm proteins, fertilin-beta and cyritestin, members of the ADAM family of proteins (A Disintegrin and Metalloprotease), are involved in sperm-egg binding. Biochemical and genetic experiments suggest there are multiple ADAM receptors on the egg. .Chemical probes containing the fertilin-beta or cyritestin binding motifs presented in either monovalent or multivalent format have been developed. These multivalent fertilin-beta mimics are the most potent fertilin-beta-derived inhibitors of fertilization to date. Moreover, these polymers cause parthenogenic egg activation resulting in resumption of meiosis. The aim of this proposal is to investigate the mechanism of action of these polymers, as well as cyritestin-derived polymers. The investigation will determine whether inhibition is due to direct competition with sperm binding or if it is due to activation of the egg block to polyspermy that results in blocking of sperm fusion. The structural requirements for inhibition versus activation will be identified as well as the egg receptors responsible. The determination of the mechanism(s) of action of the polymers will provide new leads for investigating egg-sperm adhesion, fusion, and activation of development. Understanding the mechanism of action of these compounds will provide insight into possible methods of controlling or aiding fertility.
Public Health Relevance:
This Public Health Relevance is not available.
Thesaurus Terms:
adhesion, fertilization, polymer, sperm
base, binding protein, carbohydrate, cell, cell adhesion, cell line, cell migration, chemical, extracellular, family, fertility, gene mutation, identity, insight, integrin, intracellular, lead, liposome, meiosis, membrane, metalloendopeptidase, molecular genetics, molecular probe, myoblast, peptide, phenotype, plasma, protein, protein binding, protein protein interaction, receptor, role, syndecan
Institution: STATE UNIVERSITY NEW YORK STONY BROOK
The Office of Sponsered Programs
STONY BROOK, NY 11794
Fiscal Year: 2008
Department: CHEMISTRY
Project Start: 01-MAR-2000
Project End: 31-MAR-2011
ICD: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
IRG: SBCB
Grant Number: 5R01HL053306-14
Project Title: Cholesterol Oxidase Loop Residues and Catalysis
PI Information: Name Email Title
SAMPSON, NICOLE S. nicole.sampson@stonybrook.edu ASSOCIATE PROFESSOR
Abstract: DESCRIPTION (provided by applicant): Cholesterol oxidase is a flavoenzyme that catalyzes the oxidation and isomerization of cholesterol to cholest-4-en-3-one. Cholesterol oxidase is used commercially for the determination of serum cholesterol concentrations, is insecticidal, and is used to study membrane structure. Recent evidence suggests that cholesterol oxidase may be involved in the pathogenesis of some microorganisms such as Rhodococcus equi and Mycobacterium tuberculosis. The studies proposed will provide a precise molecular model of the lipid requirements for activity and of the pathway to flavin oxidation. These models are important for the development of cholesterol oxidase as a commercial product, as a useful and reliable tool in the study of cellular membranes for monitoring lipid rafts, for investigating the role of cholesterol oxidase in bacterial pathogenesis, and for developing anti-bacterial inhibitors. The specific hypotheses that will be tested are that 1) cholesterol oxidase can distinguish between cholesterol-containing lipid domains of different composition in the same membrane, i.e., between liquid-disordered domains and liquid-ordered domains (rafts); 2) the enzyme employs a large interface to associate with the lipid bilayer during catalysis; and 3) a gated tunnel between the solvent and the flavin at the active site controls oxygen access.
Public Health Relevance:
This Public Health Relevance is not available.
Thesaurus Terms:
active site, cholesterol, enzyme mechanism, enzyme structure, hydroxysteroid dehydrogenase
conformation, enzyme activity, enzyme model, enzyme substrate complex, flavin, lipid bilayer membrane, membrane structure, molecular assembly /self assembly
X ray crystallography, chemical kinetics, site directed mutagenesis
Institution: STATE UNIVERSITY NEW YORK STONY BROOK
The Office of Sponsered Programs
STONY BROOK, NY 11794
Fiscal Year: 2009
Department: CHEMISTRY
Project Start: 01-DEC-1994
Project End: 30-NOV-2009
ICD: NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
IRG: BNP |
