Inactivation studies of cathepsin D with diazo compounds

Cathepsin D was inactivated with various diazo compounds at very high concentration. Reaction proceeded maximally at pH 4.5 in the presence of cupric ions. With 3-diazo-indazole and triazene the inactivation was noted also in the absence of cupric ions what indicates that the mechanism is mediated through triazene. CD-spectrum of partially inactivated enzyme shows that conformational changes occurred after treatment with diazo compound.