title: Purification and characterization of serine proteinase of the Glu,Asp-specific enzyme family from Thermoactinomyces species.
abstract: Enzyme catalyzing hydrolysis of a substrate of Glu,Asp-specific proteinases (Z-Glu-pNA) and cleaving bond Glu13-Ala14 in the oxidized insulin B chain was purified to homogeneity from the culture medium of Thermoactinomyces species using hydrophobic chromatography on phenyl-Sepharose CL 4B as the key purification step. The molecular weight of the proteinase is 23 kD. The enzyme is completely inhibited by diisopropyl fluorophosphate and is stable at pH 5-11. The pH optimum for the hydrolysis of azocasein as substrate is 8.5. The temperature optimum for proteolytic activity is 55 degrees C. The N-terminal sequence of the proteinase is: Ser-Val-Leu-Gly-Thr-Asp-Glu-Arg-Thr-Arg-Val-Thr-Asn-Thr-Thr-Thr-Tyr-Pro- Tyr- Trp-.
authors.affiliation: Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow, Russia.
authors.forename: I V
authors.initials: IV
authors.lastname: Demidyuk
authors.forename: E A
authors.initials: EA
authors.lastname: Nosovskaya
authors.forename: I A
authors.initials: IA
authors.lastname: Tsaplina
authors.forename: G I
authors.initials: GI
authors.lastname: Karavaiko
authors.forename: S V
authors.initials: SV
authors.lastname: Kostrov
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000737:chemistry / Q000378:metabolism; D008848:Micromonosporaceae / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D007328:Insulin; D012697:Serine Endopeptidases