title: The primary structure of alpha-amylase inhibitor Z-2685 from Streptomyces parvullus FH-1641. Sequence homology between inhibitor and alpha-amylase.
abstract: The native and oxidized alpha-amylase inhibitor Z-2685, isolated from the culture medium of Streptomyces parvullus FH-1641, and its overlapping cleavage products were degraded by the automatic Edman technique. Digestion was carried out with pepsin, thermolysin and trypsin. The alpha-amylase inhibitor is a polypeptide consisting of 76 amino acids with a molecular mass of 8 129 Da. With the exception of methionine and lysine, all naturally occurring amino acids are present. It is interesting that identical regions exist, in particular the sequence Trp-Arg-Tyr common to all four known microbial inhibitor sequences. We believe that the side chains of these three amino acids are important for interacting with the alpha-amylase molecule. Computer alignment enabled us to show a possible binding region in the alpha-amylase molecule which might react with the inhibitors. Furthermore, homology exists to mammalian alpha-amylases. This result is explained by the assumption that the inhibitor evolved from a duplication of the original gene of the enzyme.
mesh_terms: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D010084:Oxidation-Reduction; D010455:Peptides / Q000032:analysis*; D011487:Protein Conformation; D013302:Streptomyces / Q000032:analysis*; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
chemical_list: D010455:Peptides; C048177:Z 2685; D000516:alpha-Amylases