Characterization of an aminopeptidase in cerebrospinal fluid. Structure elucidation of enzyme hydrolysis products of synthetic methionine-enkephalin by reversed-phase high-performance liquid chromatography and mass spectrometry
Kusmierz, J.J.; Desiderio, D.M.
Journal of Chromatography 574(2): 189-196
1992
ISSN/ISBN: 0021-9673 PMID: 1618949 Document Number: 400604
An aminopeptidase was found in canine cerebrospinal fluid via the presence of two products: Y, which has an [M+H]+ ion at m/z 182; and GGFM, which has an [M+H]+ ion at m/z 411. The linked scan at a constant ratio of the magnetic field to the electric field of the GGFM [M+H]+ ion at m/z 411 generates product ions at m/z 120, 150, 266, 297, 354, 357, and 411. That aminopeptidase was bestatin-sensitive (BSAP = bestatin-sensitive aminopeptidase), and had a half-time for disappearance of 60 min, maximum velocity of 1.08 nmol ml-1 min-1, and Michaelis constant of 0.26 nM.