title: Promiscuity, stability and cold adaptation of a newly isolated acylaminoacyl peptidase.
abstract: We report on the characterisation of a member of the acylaminoacyl peptidase family, the first isolated from bacteria. The enzyme was obtained from the psychrophilic bacterium Sporosarcina psychrophila and shows the typical features of cold adaptation (low T(m), optimal temperature of 40 °C, poor thermal stability). It was also tested for substrate specificity, effect of metals, temperature dependence and structure stability and revealed promiscuous catalytic activity on at least two chemically distinct substrates, with k(cat)/K(m) values for ester hydrolysis and acylamino acids cleavage of 1.7 × 10(4) s(-1) M(-1) and 6.2 × 10(3) s(-1) M(-1), respectively. Despite some properties cannot be explained with current models, results report on the relevance of structural and catalytic properties for the successful adaptation to cold temperatures.
authors.affiliation: Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, 20126 Milano, Italy.
authors.forename: Electra A S
authors.initials: EA
authors.lastname: Brunialti
authors.forename: Pietro
authors.initials: P
authors.lastname: Gatti-Lafranconi
authors.forename: Marina
authors.initials: M
authors.lastname: Lotti
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D001483:Base Sequence; D003001:Cloning, Molecular; D003080:Cold Temperature; D004795:Enzyme Stability; D007700:Kinetics; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000302:isolation & purification; D058644:Sporosarcina / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D010447:Peptide Hydrolases; C038220:acylaminoacyl-peptidase