Место издания:Innovations and High Technologies MSU Ltd Moscow
Первая страница:115
Последняя страница:115
Аннотация:Penicillin acylase (EC 3.5.1.11, PA) belongs to the superfamily of N-terminal nucleophile hy-drolases. PAC is of very high importance for pharmaceutical industry and fine organic synthesis. The enzyme is used for preparation of 6-aminopenicillanic acid as well as for production of semi-synthetic penicillins and cephalosporins, as well as in fine organic synthesis and resolution of chiral compounds.
Previously we cloned gene of penicillin acylase from Alcaligenes faecalis VKM B-1518 (AfPA) and the recombinant enzyme was expressed in E. coli cells in soluble and active form. Thermal stability of AfPA was studied with thermal inactivation kinetics. In present work we studied thermal stability of AfPA with differential scanning calorimetry. Peak position (melting temperature Tm) and value of heat capacity cp did not depend on protein concentration in range 1.5 – 6 mg/ml. Increase of heating rate at constant AfPA concentration resulted in increase of Tm value but the value of heat ca-pacity was again constant. Data obtained show that thermal denaturation of the AfPA proceeds through one step without dissociation of heterodimeric enzyme in separate subunits. It is in agreement with data of thermal inactivation kinetics.
The work was supported by Russian Foundation for Basic Research (RFBR), grant 13-04-01907-а.