Avtor/Urednik		Turk, Boris; Bieth, Joseph G; Bjork, Ingemar; Dolenc, Iztok; Turk, Dušan; Cimerman, Nina; Kos, Janko; Čolič, Adrijana; Stoka, Veronika; Turk, Vito
Naslov		Regulation of the activity of lysosomal cysteine proteinases by pH-induced inactivation and/or endogenous protein inhibitors, cystatins
Tip		članek
Vir		Biol Chem Hoppe Seyler
Vol. in št.		Letnik 376, št. 4
Leto izdaje		1995
Obseg		str. 225-30
Jezik		eng
Abstrakt		The kinetics of pH-induced inactivation of human cathepsins B and L was studied by conventional and stopped-flow methods. The inactivation of both enzymes was found to be an irreversible, first-order process. The inactivation rate constants increased exponentially with pH for both enzymes. From log kinac vs pH plots, 3.0 and 1.7 protons were calculated to be desorbed for pH-induced inactivation of cathepsins L and B. Cathepsin B was thus substantially more stable than cathepsin L (approximately 15-fold at pH 7.0 and 37 degrees C). Cathepsin B was efficiently inhibited by cystatin C at pH 7.4, whereas the inhibition by stefin B and high molecular weight kininogen was only moderate. In contrast, cathepsin L was efficiently inhibited by both chicken cystatin and stefin B at this pH kass approximately 3.3 x 10(7) m-1 s-1).
Deskriptorji		CYSTATINS CYSTEINE PROTEINASES LYSOSOMES CATHEPSIN B CATHEPSINS CHICKENS HYDROGEN-ION CONCENTRATION KINETICS