Open AccessThe Enzymatic Breakdown of Pantethine to Pantothenic Acid and Cystamine
Author(s) -
Duprè Silvestro,
Graziani Maria Teresa,
Rosei Maria Anna,
Fabi Andrea,
Grosso Elena
Publication year - 1970
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1970.tb01119.x
Subject(s) - cystamine , enzyme , chemistry , substrate (aquarium) , dithiothreitol , biochemistry , cysteamine , enzyme assay , biology , ecology
The enzyme splitting pantethine into pantothenic acid and cystamine has been purified about 3000 times starting from horse kidney. The purification procedure is reported. The enzyme, whose optimal activity lies in the pH range 4.0–5.5, requires the presence of a reduced thiol for the full activity: mercaptoethanol and dithiothreitol give the higher effect. This activation seems not to be specific. The enzyme has a K m value for the substrate of the order of 5 mM and shows inhibition by excess substrate and by products. Substrate specificity studies show that the enzyme splits only the intact substrate molecule, which is not hydrolyzed by several hydrolytic enzymes, even with a broad specificity (as bacterial pronase and subtilisin). The enzyme could be responsible for the production in vivo of cysteamine, which is known to be oxydized by a specific oxygenase, isolated recently in this laboratory.