EVIDENCE OF AN INTERMEDIATE-SIZED BETA-ENDORPHIN-CONTAINING PRECURSOR MOLECULE IN BOVINE PITUITARY BY MASS-SPECTROMETRY

A new analytical system has been designed to characterize intermediate-sized precursor molecules from two different precursors - the preproenkephalin A(bovine,1-263) precursor molecule, which produces methionine enkephalin and from the proopiomelanocortin, POMC(bovine,1-265) precursor molecule, which produces β-endorphin. A possible intermediate-sized precursor that leads to β-endorphin was found in bovine pituitary by means of electrospray ionization mass spectrometry, in combination with gel permeation chromatography, reversed-phase high performance liquid chromatography, radioimmunoassay, trypsinolysis, and liquid secondary ion mass spectrometry. © 1993 Academic Press, Inc.