Triosephosphate Isomerase of Pea Seeds

Abstract

An active preparation of triosephosphate isomerase was obtained from pea seeds. All other plant tissue extracts examined showed triosephosphate isomerase activity. The enzyme had an optimum pH of 7.2-8.9 and, under the experimental conditions used, the Michaelis-Menten constant for D-glyceraldehyde-3-phosphate was 3.6 x 10-4 [image]. Sulfate ions, and to a lesser extent chloride ions inhibited the enzyme. Inorganic phosphate, arsenate, p-chloromercuribenzoate, and Cu2+ ions also reduced enzyme activity.