Portland State University. Department of Biology
David T. Clark
Date of Award
Master of Science (M.S.) in Biology
1 online resource (51 p.)
Methionine -- Metabolism, Fasciola hepatica
5'-Deoxy-5'-methylthioadenosine (MTA) is derived from s-adenosylmethionine (AdoMet) during the synthesis of the polyamines spermidine and spermine. Methionine can be regenerated from MTA by one of two mechanisms. In mammalian cells and some microorganisms, MTA is degraded to adenine and 5-methylthioribose-1-phosphate (MTR-1-P) via MTA phosphorylase. In certain other microbes, however, MTA is catabolized in two steps; first to adenine and 5-methylthioribose (MTR) via MTA nucleosidase followed by conversion of MTR to MTR-1-P via MTR kinase.
This study was to demonstrate the presence of MTA nucleosidase or MTA phosphorylase in both redia containing cercariae and adult Fasciola hepatica Linnaeus, 1758. If MTA nucleosidase was present, it was wanted to determine if MTR kinase was also present.
The phosphate-dependent cleaving activity of MTA phosphorylase was demonstrated in the cell-free extracts of adult Fasciola hepatica along with an unidentified MTR metabolizing activity. Redia containing cercariae showed MTA nucleosidase and MTR kinase activity.
Ayer, Carol Theresa, "Methionine Metabolism in Fasciola Hepatica" (1990). Dissertations and Theses. Paper 3954.