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A determination of the positions of disulphide bonds in Paim I, α‐amylase inhibitor from Streptomyces corchorushii , using fast atom bombardment mass spectrometry
Author(s) -
Akashi Satoko,
Hirayama Kazuo,
Seino Tadatoshi,
Ozawa Shinichi,
Fukuhara Kenichi,
Oouchi Naoki,
Murai Asao,
Arai Motoo,
Murao Sawao,
Tanaka Kazuo,
Nojima Ittetsu
Publication year - 1988
Publication title -
biomedical and environmental mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0887-6134
DOI - 10.1002/bms.1200151006
Subject(s) - chemistry , fast atom bombardment , mass spectrometry , cystine , protease , chromatography , enzyme , amylase , molecular mass , amino acid , stereochemistry , cysteine , biochemistry
Paim I, a protein α‐amylase inhibitor, is a single‐chain polypeptide which consists of 73 amino acids, including 4 half‐cystine residues. The positions of disulphide bonds in Paim I have been determined with the combination of enzymatic digestion and fast atom bombardment (FAB) mass spectrometry. Denatured Paim I was digested to peptides with Staphylococcus aureus V8 protease. These peptides were subjected to FAB mass spectrometry, with or without isolation by high‐performance liquid chromatography. The positions of disulphide bonds in Paim I were determined from the relative molecular masses of the peptides containing a disulphide bond and by the enzyme specificity of S. aureus V8 protease. It is deduced that Paim I has two disulphide bridges at Cys(8)‐Cys(24) and Cys(42)‐Cys(70).