title: A low molecular mass cutinase of Thielavia terrestris efficiently hydrolyzes poly(esters).
abstract: A low molecular mass cutinase (designated TtcutA) from Thielavia terrestris was purified and biochemically characterized. The thermophilic fungus T. terrestris CAU709 secreted a highly active cutinase (90.4 U ml(-1)) in fermentation broth containing wheat bran as the carbon source. The cutinase was purified 19-fold with a recovery yield of 4.8 %. The molecular mass of the purified TtcutA was determined as 25.3 and 22.8 kDa using SDS-PAGE and gel filtration, respectively. TtcutA displayed optimal activity at pH 4.0 and 50 °C. It was highly stable up to 65 °C and in the broad pH range 2.5-10.5. Extreme stability in high concentrations (80 %, v/v) of solvents such as methanol, ethanol, acetone, acetonitrile, isopropanol, and dimethyl sulfoxide was observed for the enzyme. The K                 (m) values for this enzyme towards p-nitrophenyl (pNP) acetate, pNP butyrate, and pNP caproate were 7.7, 1.0, and 0.52 mM, respectively. TtcutA was able to efficiently degrade various ester polymers, including cutin, polyethylene terephthalate (PET), polycaprolactone (PCL), and poly(butylene succinate) (PBS) at hydrolytic rates of 3 μmol h(-1) mg(-1) protein, 1.1 mg h(-1) mg(-1) protein, 203.6 mg h(-1) mg(-1) protein, and 56.4 mg h(-1) mg(-1) protein, respectively. Because of these unique biochemical properties, TtcutA of T.                 terrestris may be useful in various industrial applications in the future.
authors.affiliation: Department of Biotechnology, College of Food Science and Nutritional Engineering, China Agricultural University, PO Box 294, No. 17 Qinghua Donglu, Haidian District, Beijing 100083, China.
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Yang
authors.forename: Haibo
authors.initials: H
authors.lastname: Xu
authors.forename: Qiaojuan
authors.initials: Q
authors.lastname: Yan
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Peng
authors.initials: P
authors.lastname: Zhou
authors.forename: Zhengqiang
authors.initials: Z
authors.lastname: Jiang
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D004795:Enzyme Stability; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry / Q000378:metabolism*; D012997:Solvents / Q000737:chemistry; D020037:Sordariales / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D011091:Polyesters; D012997:Solvents; D002265:Carboxylic Ester Hydrolases; C019952:cutinase