Mechanism-based inactivation of l-pipecolate oxidase by a sulfur-containing substrate analog, 5-thia- l-pipecolic acid

Abstract

5-Thia- l-pipecolic acid, ( S)-1,3-thiazane-4-carboxylic acid ( 6), was synthesized and found to serve as an excellent substrate for Rhesus monkey liver l-pipecolate oxidase ( l-PO) and also to cause time-dependent, irreversible inactivation of the enzyme. Data are presented demonstrating 6 is a mechanism-based inactivator of L-PO and one of the enzyme turnover products is identified as homocysteine.