Xu_2015_Food.Chem_188_439

An acidic cutinase (TtcutB) from Thielavia terrestris CAU709 was purified to apparent homogeneity with 983Umg(-1) specific activity. The molecular mass of the enzyme was estimated to be 27.3 and 27.9kDa by SDS-PAGE and gel filtration, respectively. A peptide sequence homology search revealed no homologous cutinases from T. terrestris, except for one putative cutinase gene (XP003656017.1), indicating that TtcutB is a novel enzyme. TtcutB exhibited an acidic pH optimum of 4.0, and stability at pH 2.5-10.5. Optimal activity was at 55 degrees C, it was stable up to 65 degrees C, and retained over 30% activity at 0 degrees C. Km values toward p-nitrophenyl (pNP) acetate, pNP-butyrate and pNP-caproate were 8.3, 1.1 and 0.88mM, respectively. The cutinase exhibited strong synthetic activity on flavor ester butyl butyrate under non-aqueous environment, and the highest esterification efficiency of 95% was observed under the optimized reaction conditions. The enzyme's unique biochemical properties suggest great potential in flavor esters-producing industries.