Endocrinology, Vol 120, 1472-1476, Copyright © 1987 by Endocrine Society
In vitro lipolytic activity of beta-endorphin and its partial sequences
WO Richter, RJ Naude, W Oelofsen and P Schwandt
beta-Endorphin stimulates glycerol release from adipose tissue in vitro in
the rabbit. Thirty different amino acid sequences of this peptide were
tested for lipolytic activity. Four turned out to be active: porcine and
human beta-endorphin-(1-31), human beta-endorphin-(6-31), and human
beta-endorphin-(1-5)-(16-31). Structure-activity investigations showed that
for the lipolytic action of beta-endorphin the C-terminal part [longer than
beta-endorphin-(27-31)] is relatively important. Of special importance
seems to be the C-terminal amino acid residue, because none of the
sequences lacking the last two amino acid residues was lipolytically
active. Furthermore, a different lipolytic response to beta-endorphin was
obtained in starved, ad libitum-fed, and starved-refed animals, showing
that the regulation of the lipolytic potency is not only mediated by
peptide concentrations in the medium.
