ON THE ANALYSIS OF BOVINE TRYPSIN BY ELECTROSPRAY MASS-SPECTROMETRY

In this paper the results obtained from an electrospray mass spectrome tric (ES-MS) analytical study of commercial grade bovine trypsin are p resented and discussed. It is proven, somewhat contrary to an earlier report, that ES-MS analysis may be performed routinely on a triple qua drupole mass spectrometer using the normal ES-MS raw data transformati on procedures to identify and quantify the three forms of trypsin, nam ely, beta, alpha( )and psi, present in the samples. Further, it was fo und that all of the samples analysed contained small amounts of two pe ptides of Mr=5447 and 17,882 Da, which are postulated to originate fro m catalytic cleavage of alpha-trypsin by beta P-trypsin. (C) 1994 Acad emic Press, Inc.