title: Extracellular serine-proteinases isolated from Streptomyces alboniger: partial characterization and effect of aprotinin on cellular structure.
abstract: Streptomyces alboniger ATCC 12461 grown in brain heart infusion (BHI) medium produced two extracellular serine-proteinases, denoted SP I and SP II, which were purified by ammonium sulfate precipitation and aprotinin-agarose affinity chromatography. SP I was purified 88,9-fold and SP II 66,7- fold, with 33.4% and 10.4% yield, respectively. The optimum pH for the proteinases activity, using a-N-p-tosyl-L-arginine-methyl ester (TAME) as substrate, was 9-10 and the optimum temperature was 37 degrees C. The proteolytic activity of SP I and SP II was inhibited by aprotinin and SP I was partially inhibited by leupeptin, both serine-proteinase inhibitors. S. alboniger growth in BHI-liquid medium decreased when 5 mg/ml, 10 mg/ml of aprotinin was used, being completely inhibited with 20 mg/ml and 40 mg/ml. At the ultrastructural level, aprotinin-treated S. alboniger cells showed swelling of the bacterial body and condensation of the genetic material, probably related to the inhibition of its growth.
authors.affiliation: Departamento de Microbiologia Geral, Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21949-900, Brasil.
authors.forename: A
authors.initials: A
authors.lastname: Lopes
authors.forename: R R
authors.initials: RR
authors.lastname: Coelho
authors.forename: M N
authors.initials: MN
authors.lastname: Meirelles
authors.forename: M H
authors.initials: MH
authors.lastname: Branquinha
authors.forename: A B
authors.initials: AB
authors.lastname: Vermelho
mesh_terms: D007611:Aprotinin / Q000494:pharmacology*; D002473:Cell Wall / Q000187:drug effects; D012697:Serine Endopeptidases / Q000302:isolation & purification*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D013302:Streptomyces / Q000187:drug effects* / Q000201:enzymology* / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D015842:Serine Proteinase Inhibitors; D007611:Aprotinin; D012697:Serine Endopeptidases