IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Deactivation Kinetics and Response Surface Analysis of the Stability of alpha-L-Rhamnosidase from Penicillium decumbens
Autor/es:
IVANA MAGARIO; ANKE NEUMANN; ESTHER OLIVEROS; CHRISTOPH SYLDATK
Revista:
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
Editorial:
SpringerLink
Referencias:
Lugar: Heidelberg; Año: 2009
ISSN:
0273-2289
Resumen:
The stability of the mixed enzyme preparation Naringinase from Penicillium decumbens was studied in dependence of the temperature, the pH value, and the enzyme concentration by means of response surface methodology. Deactivation kinetics by formation of an intermediate state was proposed for fitting deactivation data. Empirical models could then be constructed for prediction of deactivation rate constants, specific activity of intermediate state, and half-life values under different incubation conditions. From this study, it can be concluded that (1) Naringinase is most stable in the pH range of 4.5–5.0, being quite sensitive to lower pHs (<3.5) and (2) the glyco-enzyme is a rather thermo-stable enzyme preserving its initial activity for long times when incubated at its optimal pH up to temperatures of 65 °C. Enriched alpha-L-rhamnosidase after column treatment and ultrafiltration presented similar deactivation kinetics pattern and half-life values as the unpurified enzyme. Thus, any influence of low molecular weight substances on its deactivation is most probably negligible. The intermediate state of the enzyme may correspond to unfolding and self-digestion of its carbohydrate portion, lowering its activity relative to the initial state. The digestion- and unfolding-grade of this intermediate state may also be controlled by the pH and temperature of incubation.