A protein disulphide reductase from pea seeds

Publisher Website
Google Scholar
Abstract
Protein disulphide reductase, which catalyses the reduction of protein disulphide groups, was purified approximately 40-fold from pea-seed extracts. The enzyme utilized reduced di- and triphosphopyridine nucleotide to reduce protein-disulphide groups. The rate of reaction with reduced triphosphopyridine nucleotide was approximately twice that with reduced diphosphopyridine nucleotide. A protein fraction from pea seeds was used as substrate in most experiments. The enzyme also reduced disulphide groups of a pea-seed glyceraldehyde 3-phosphate-dehydrogenase preparation and of some other enzymes and proteins. Cystine reductase and glutathione reductase, both of which were present in crude pea-seed extracts, were not involved in the reduction of protein-disulphide groups. The effects of pH and concentration of reduced triphosphopyridine nucleotide on the enzyme activity were studied. Protein disulphide-reductase activity was strongly inhibited by low concentrations of p-chloromercuribenzoate, iodoacetate, Hg2+ ions, Ag+ ions, Cu2+ ions, Cd2+ ions, Zn2+ ions and arsenite. Active preparations of the enzyme were obtained from a number of plant tissues. A possible, mechanism of action of protein disulphide reductase is presented.