Date of Award

Spring 1991

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry and Biochemistry

Program/Concentration

Biomedical Sciences

Committee Director

James H. Yuan

Committee Member

Keith Carson

Committee Member

Laura K. Moen

Committee Member

Nancy J. Alexander

Abstract

The goal of this project was to study the mechanism of action of gossypol through its (a) binary interaction with native and trypsin digested lactate dehydrogenase-X (LD-X), a sperm-specific isozyme, and (b) its binding in vitro in primary cultures of spermatogenic cells. Mouse LD-X was cleaved with trypsin before and after treatment with gossypol. This was followed by high performance chromatography (HPLC) separation of the LD-X tryptic peptide fragments to observed alterations in separation patterns as indicators of intramolecular disturbance in the enzyme molecule. Definite alterations in peptide fragment peaks were observed in the presence of gossypol and suggest conformational or intramolecular modifications in the enzyme structure attributable to direct binding with gossypol or its degradation products. Whether there are gossypol interactions unique for LD-X was not determined. The binding of 14C-gossypol to cytosolic and membrane fractions of spermatogenic cell suspensions revealed that most of the gossypol was located in the membrane fractions. However, the relative amount of LD-X bound gossypol was greater in the cytosol than the membrane fractions. A model of gossypol binding in spermatogenic cells is proposed.

Comments

Dissertation submitted to the Faculty of Eastern Virginia Medical School and Old Dominion University in Partial Fulfillment of the Requirement for the Degree of Doctor of Philosophy in Biomedical Sciences.

DOI

10.25777/6swe-b588

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