title: A cold-adapted extracellular serine proteinase of the yeast Leucosporidium antarcticum.
abstract: An extracellular serine proteinase, lap2, from the psychrophilic antarctic yeast Leucosporidium antarcticum 171 was purified to homogeneity and characterized. The enzyme is a glycoprotein with a molecular mass of 34.4 kDa and an isoelectric point of pH 5.62. The proteinase is halotolerant, and its activity and stability are dependent neither on Ca(2+) nor on other metal ions. Lap2 is a true psychrophilic enzyme because of low optimal temperature (25 degrees C), poor thermal stability, relatively small values of free energy, enthalpy and entropy of activation, and high catalytic efficiency at 0-25 degrees C. The 35 N-terminal amino acid residues of lap2 have homology with subtilases of the proteinase K subfamily (clan SB, family S8, subfamily C). The proteinase lap2 is the first psychrophilic subtilase in this family.
authors.affiliation: Institute of Technical Biochemistry, Technical University of Łódź, ul. Stefanowskiego 4/10, 90-924 Łódź, Poland. mtur@ck-sg.p.lodz.pl
authors.forename: Marianna
authors.initials: M
authors.lastname: Turkiewicz
authors.forename: Marzena
authors.initials: M
authors.lastname: Pazgier
authors.forename: Halina
authors.initials: H
authors.lastname: Kalinowska
authors.forename: Stanisław
authors.initials: S
authors.lastname: Bielecki
mesh_terms: D000595:Amino Acid Sequence; D003080:Cold Temperature; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012697:Serine Endopeptidases / Q000235:genetics / Q000302:isolation & purification*; D013379:Substrate Specificity; D013696:Temperature; D015003:Yeasts / Q000201:enzymology* / Q000235:genetics
chemical_list: D012697:Serine Endopeptidases