Isolation and structure elucidation of an alpha-amylase inhibitor, AI-3688, from Streptomyces aureofaciens.
A novel polypeptide inhibitor, AI-3688, which acts upon human pancreatic alpha-amylase, was isolated from fermentation broth of Streptomyces aureofaciens. The purified peptide contains no unusual amino acids. Its Mr is 3936. The primary structure of AI-3688 was elucidated by automatic Edman degradation of the native or modified inhibitor. Two intramolecular cysteines form a disulphide bridge, thus creating a ring structure consisting of 17 amino acids. Strong sequence homology also exists to another microbial alpha-amylase inhibitor, tendamistat (HOE 467). This paper discusses the role of a common partial sequence, -Gln-Ser-Trp-Arg-Tyr-, present in the loop of both inhibitors as the active site of microbial peptide alpha-amylase inhibitors.
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D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000681:Amylases / Q000037:antagonists & inhibitors; D001412:Bacillus subtilis / Q000201:enzymology; D055598:Chemical Phenomena; D002621:Chemistry; D004220:Disulfides; D036341:Intercellular Signaling Peptides and Proteins; D010179:Pancreas / Q000201:enzymology; D010455:Peptides / Q000302:isolation & purification* / Q000494:pharmacology; D012463:Saliva / Q000201:enzymology; D013304:Streptomyces aureofaciens / Q000378:metabolism*; D014508:Urea / Q000494:pharmacology; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
C045538:AI 3688; D000596:Amino Acids; D004220:Disulfides; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D014508:Urea; D000681:Amylases; D000516:alpha-Amylases