Isolation of a heptapeptide Val-Val-Tyr-Pro-Trp-Thr-Gln (valorphin) with some opiate activity.
Bovine hypothalamic tissue was extracted and purified by solid phase extraction and several reversed-phase HPLC steps. The amino acid sequence of the purified peptide was determined by Edman degradation to be Val-Val-Tyr-Pro-Trp-Thr-Gln. This was confirmed by comparison of its chromatographic behavior with that of the synthetic peptide, and mass spectrometric analysis resulted in a mass identical to the calculated mass for this peptide. This heptapeptide shows homology with residues 32-38 of the beta-chain of bovine hemoglobin. The peptide inhibited the electrically induced contractions of the guinea pig ileum muscle preparation; this inhibition was reversible by naloxone. It also inhibited the binding of 125I-DAMGO (selective for mu receptors) to rat brain with an IC50 of 10 microM and the binding of 3H-DPDPE (selective for sigma receptors) with an IC50 of 185 microM. With two valines at the N-terminus and some opiate activity, valorphin seems a suitable name for this newly isolated peptide.
VA Medical Center, New Orleans, LA.
J
J
Erchegyi
A J
AJ
Kastin
J E
JE
Zadina
X D
XD
Qiu
D000218:Adamantane / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000302:isolation & purification / Q000494:pharmacology; D000595:Amino Acid Sequence; D000701:Analgesics, Opioid / Q000138:chemical synthesis / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D001681:Biological Assay; D002417:Cattle; D006168:Guinea Pigs; D007031:Hypothalamus / Q000737:chemistry; D007082:Ileum / Q000187:drug effects; D008297:Male; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects; D011869:Radioligand Assay
D000701:Analgesics, Opioid; C045483:valorphin; D000218:Adamantane