RESUMEN
Bovine liver catalase (EC 1.11.1.6) was chemically modified with mannan, carboxymethylcellulose, and carboxymethylchitin. The enzyme retained about 48-97% of the initial specific activity after glycosidation with the polysaccharides. The prepared neoglycoenzyme was 1.9-5.7 fold more stable against the thermal inactivation processes at 55 degrees C, in comparison with the native counterpart. Also, the modified enzyme was more resistant to proteolytic degradation with trypsin. Pharmacokinetics studies revealed higher plasma half-life time for all the enzyme-polymer preparations, but better results were achieved for the enzyme modified with the anionic macromolecules.
Asunto(s)
Catalasa/farmacocinética , Polisacáridos/química , Animales , Área Bajo la Curva , Secuencia de Carbohidratos , Carboximetilcelulosa de Sodio/química , Carboximetilcelulosa de Sodio/metabolismo , Catalasa/administración & dosificación , Catalasa/química , Bovinos , Estabilidad de Enzimas , Semivida , Calor , Concentración de Iones de Hidrógeno , Inyecciones Intravenosas , Hígado/enzimología , Masculino , Datos de Secuencia Molecular , Estructura Molecular , Ratas , Ratas Wistar , Solubilidad , Espectrofotometría , Especificidad por Sustrato , Agua/químicaRESUMEN
An enzymatic approach, based on a transglutaminase-catalyzed coupling reaction, was investigated to modify bovine liver catalase with an end-group aminated dextran derivative. We demonstrated that catalase activity increased after enzymatic glycosidation and that the conjugate was 3.8-fold more stable to thermal inactivation at 55 degrees C and 2-fold more resistant to proteolytic degradation by trypsin. Moreover, the transglutaminase-mediated modification also improved the pharmacokinetics behavior of catalase, increasing 2.5-fold its plasma half-life time and reducing 3-fold the total clearance after its i.v. administration in rats.