Isolation and characterization of beta-endorphin-(1-9) from human and rat pituitaries.
Using a radioimmunoassay specific for the carboxyl terminus of beta-endorphin-(1-9) large amounts of beta-endorphin-(1-9)-immunoreactive material was detected in the human pituitary. The major peak of immunoreactivity was purified and characterized by fast atom bombardment-mass spectrometry and Edman degradation sequencing as authentic beta-endorphin-(1-9). In the rat pituitary the highest concentration of beta-endorphin-(1-9) immunoreactivity was in the posterior neurointermediate lobe. This material was identified as N-acetyl beta-endorphin-(1-9) by multiple radioimmunoassays, gel chromatography, and reversed-phase high-performance liquid chromatography. Control experiments determined that beta-endorphin-(1-9) was not formed postmortem or during the extraction procedure. These studies suggest that single lysine residues, similar to single arginine residues, are potential sites of posttranslational processing.
Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110.
K A
KA
Roth
R A
RA
Unanue
J
J
Leykam
A N
AN
Tyler
D000328:Adult; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D013058:Mass Spectrometry; D010902:Pituitary Gland / Q000032:analysis*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains