Inactivation of pancreatic ribonuclease with hydroxylamine-oxygen-cupric ion

Abstract

In the studies of ribonuclease, it was found that a system containing hydroxylamine, Cn 2+ and O 2 will inactivate its biological activity. All three components are essential for the inactivation. The inactivation of ribonuclease by this system is pH-dependent. The rate of inactivation was studied as a function of hydroxylamine concentration and Cu 2+ concentration. It is interesting to note that both Tris and phosphate serve as competitive inhibitors. It was also found that all four histidine residues of ribonuclease were missing when the inactivated ribonuclease was subjected to acid hydrolysis followed by amino acid analysis.