Rapid high-yield purification of canine intestinal motilin and its complete sequence determination.

Canine motilin has been purified from small amounts of canine intestine in a form suitable for microsequence analysis. The sequence determined is: Phe-Val-Pro-Ile-Phe-Thr-His-Ser-Glu-Leu-Gln-Lys-Ile-Arg-Glu-Lys-Glu-Arg- Asn-Lys - Ile-Arg-Asn-Lys-Gly-Gln. Canine motilin differs from porcine motilin at five positions. The rapid, high-yield (24% overall yield) microisolation techniques used for canine motilin should be suitable for the isolation of other basic peptides found in low levels in tissue that is available only in limited amounts. These methods should make the isolation and sequence determination of human brain and gut peptides more readily achievable.