PURIFICATION AND CHARACTERIZATION OF ALKALINE SERINE-PROTEASE FROM ANALKALOPHILIC STREPTOMYCES SP

SAP, an extracellular alkaline serine protease produced by Streptomyce s sp. YSA-130, was purified to homogeneity by CM-Sephadex column chrom atography and crystallization. The enzyme was a monomeric protein with a molecular weight of 19,000 as estimated by SDS-PAGE and gel filtrat ion. The amino acid composition and amino-terminal sequence of SAP wer e similar to those of other bacterial serine proteases, i.e., Streptom yces griseus proteases A and B, Lysobacter enzymogenes alpha-lytic pro tease and Nocardiopsis dassonvillei subsp. prasina OPC-210 alkaline se rine protease NDP-1. The optimum temperature and pH for the enzyme act ivity were 60-degrees-C and 11.5. The enzyme was stable up 50-degrees- C, and between pHs 4 and 12. The activity was inhibited by Ag+, Hg2+, Co2+, Sodium dodecyl sulfate, N-bromosuccinimide, diisopropyl phosphor ofluoridate (DFP), 2,3-butanedione, 5,5'-dithiobis-(2-nitrobenzoic aci d) (DTNB), iodoacetate, N-ethylmaleimide (NEM), phenylmethanesulfonyl fluoride (PMSF), and phenylglyoxal.