Neo‐kyotorphin (Thr—Ser—Lys—Tyr—Arg), a new analgesic peptide

Abstract

The amino acid sequence of a newly isolated pentapeptide, neo‐kyotorphin from bovine brain was synthetically verified to be Thr‐Ser‐Lys‐Tyr‐Arg corresponding to the C‐terminal portion of hemoglobin α‐chain. The synthetic neo‐kyotorphin showed the dose‐dependent analgesia in mice which was approximately equal to that of Leu‐enkephalin.