New proteinaceous α-amylase inhibitor (T-76) from Streptomyces nitrosporeus

Abstract

An actinomycete, strain no. T-76, which a produced new proteinaceous α-amylase inhibitor, was isolated from soil. The strain was identified as Streptomyces nitrosporeus from its taxonomical characteristics. The inhibitor, tentatively named T-76 was purified from the culture filtrate by ammonium sulfate precipitation, DEAE and TEAE cellulose column chromatography, acid precipitation, and Octyl Sepharose hydrophobic chromatography. The molecular weight and isoelectric point of the inhibitor were estimated to be 8,000 and 4.0, respectively. The amino acid composition of the inhibitor was different from that of proteinaceous inhibitors of other strains. The inhibition spectrum of the inhibitor was also different from that of other origins.