Heterologous expression of an esterase from Thermus thermophilus HB27 in Saccharomyces cerevisiae

In this work, a system for high-level secretion by Saccharomyces cerevisiae of the Thermus thermophilus HB27 putative esterase YP(-)004875.1 was constructed. The recombinant protein was purified and partially characterised. Its lipolytic activity dropped abruptly when the acyl chain length of the substrate increased from 12 to 18 carbon atoms, and variation of the reaction rate as function of substrate concentration followed Michaelis-Menten kinetics. These results suggested that the enzyme was an esterase. The recombinant enzyme was N-glycosylated and both the glycosylated and non-glycosylated forms showed activity. Compared to the native enzyme, thermal stability (half-life of 4.3 h at 85 degrees C) was higher, optimum temperature (40 degrees C) was lower and optimum pH (7.5-8.5) was similar. These characteristics support potential biotechnological applications of the recombinant esterase. (C) 2009 Elsevier B.V. All rights reserved.