title: Functional characterization of a novel aspartic acid rich lipase, TALipC, from Trichosporon asahii MSR54: solvent-dependent enantio inversion during esterification of 1-phenylethanol.
abstract: A novel lipase gene TAlipC was isolated from Trichosporon asahii MSR54 and functionally expressed in Pichia pastoris. The protein was His-tagged and purified to homogeneity by affinity chromatography. Sequence comparison revealed a high homology with lipases from Cryptococcus sp. It had a GX type oxyanion hole and a GHSLG-type conserved penta-peptide similar to those in the lipases from Yarrowia lipolytica. The enzyme had optimal activity at pH 8 and 50 °C. It was specific for long chain fatty acid groups of p-nitrophenol esters and triacylglycerols, showing regio- and enantio-selectivity. It was activated by Mg(2+) ions (20 mM) and had a predicted Mg-binding domain at the aspartic acid-rich C-terminal. Solvent-based enantio- inversion was the key feature of the enzyme where it showed (S)-selectivity in 1,4-dioxane and 2-propanol and (R)-selectivity in hexane during chiral separation of (±)1-phenylethanol by esterification.
authors.affiliation: Department of Microbiology, University of Delhi South Campus, New Delhi, 110021, India.
authors.forename: Arti
authors.initials: A
authors.lastname: Kumari
authors.forename: Rani
authors.initials: R
authors.lastname: Gupta
mesh_terms: D000595:Amino Acid Sequence; D001224:Aspartic Acid; D001592:Benzyl Alcohols / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D004795:Enzyme Stability; D004951:Esterification; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013237:Stereoisomerism; D014250:Trichosporon / Q000201:enzymology*
chemical_list: D001592:Benzyl Alcohols; D005656:Fungal Proteins; D001224:Aspartic Acid; C002017:methylphenyl carbinol; D008049:Lipase