Beta-endorphin-like immunoreactivity in extracts of the fetal bovine pancreas. Column chromatographic characterizations of a high-molecular-weight immunoreactive species.

Acid-ethanol extracts of fetal bovine pancrease were examined for the presence of beta-endorphin-like immunoreactivity. Gel-filtration analyses revealed the presence of a major large-molecular-weight beta-endorphin immunoreactive species of approximately 20K delta. This molecular form maintained its size upon resubmission to gel filtration in the presence of 6 M guanidine hydrochloride, separated from the bulk of the glucagon immunoreactivity upon ion-exchange chromatography, showed proportional dilution in the beta-endorphin radioimmunoassay, and interacted in a biospecific manner with Concanavalin-A-Sepharose.