Determination of the primary structure of Paim II, an alpha-amylase inhibitor from Streptomyces coruchorushii, by high-performance tandem mass spectrometry

This study indicates one of the advantages of tandem mass spectrometry; the primary structures of proteins with little structural difference can be determined by using tandem mass spectrometry without prior purification of each component. The primary structure of Paim II, a protein alpha-amylase inhibitor from Streptomyces coruchorushii, was determined by using tandem mass spectrometry. Paim II consists of two component proteins with ragged N-terminus, and was sequenced on the basis of the structure of Paim I, an analogous alpha-amylase inhibitor from the same natural origin.