Avtor/Urednik		Turk, B; Dolenc, I; Žerovnik, E; Turk, D; Gubenšek, F; Turk, V
Naslov		Human cathepsin B is a metastable enzyme stabilized by specific ionic interactions associated with the active site
Tip		članek
Vir		Biochemistry
Vol. in št.		Letnik 33, št. 49
Leto izdaje		1994
Obseg		str. 14800-6
Jezik		eng
Abstrakt		The effect of neutral or alkaline pH on cathepsin B activity and structure was investigated. An irreversible loss of activity, accompanied by large structural changes, was observed at pH more th. or = 7.0. The high activation energy of 183.5 kJ mol-1, calculated for the inactivation process, is in good agreement with structural changes observed by circular dichroism. Both the pH-induced inactivation and the pH-induced unfolding of cathepsin B were found to be first-order processes, exponentially increasing with increasing pH of the solution. The good agreement of the rate constants of inactivation and unfolding of the enzyme indicates an important structure-function relationship. Cathepsin B was also found to be destabilized both by increasing ionic strength and organic solvent content.
Deskriptorji		CATHEPSIN B BINDING SITES CIRCULAR DICHROISM ENZYME STABILITY HYDROGEN-ION CONCENTRATION KINETICS MODELS, CHEMICAL MODELS, MOLECULAR OSMOLAR CONCENTRATION PROTEIN CONFORMATION SPLEEN TEMPERATURE