title: Purification and amino acid sequence of motilin from cat small intestine.
abstract: Motilin was isolated from cat small intestine by a series of chromatographic steps. Using a radioreceptor assay, based upon binding of iodinated porcine motilin to rabbit antral smooth muscle membranes, it was shown that cat duodenal mucosa contains about 495 ng/g tissue, the jejunal mucosa 161 ng/g tissue and the ileal mucosa 95 ng/g tissue motilin. The duodenal mucosa was extracted with 6% acetic acid and concentrated on a cation exchange Whatman CM-52 gel. After lyophilization the material was further purified by gel filtration (Sephadex G-50), followed by reverse phase (C18), cation exchange HPLC (Mono S) and three runs on a reverse phase HPLC (Nucleosil 300-5C18) column. The UV absorbance and the radioreceptor assay were used to monitor the purification. After Mono S chromatography two forms of motilin were detected. The major peak corresponded to a 22 amino acid peptide, which differed only from canine motilin at position 12, where Lys is replaced by Arg. The smaller peak probably corresponds to a deamidated form of this peptide. The sequence homology between cat and porcine/human motilin or cat and rabbit motilin is 81.8% and 72.7%, respectively. The conservation of the first six amino acids in all five species studied is striking, confirming that the biological activity of the peptide resides in the N-terminal part.
authors.affiliation: Gut Hormone Laboratory, K.U.L., Leuven, Belgium.
authors.forename: I
authors.initials: I
authors.lastname: Depoortere
authors.forename: T L
authors.initials: TL
authors.lastname: Peeters
authors.forename: A
authors.initials: A
authors.lastname: Vandermeers
authors.forename: M C
authors.initials: MC
authors.lastname: Vandermeers-Piret
authors.forename: J
authors.initials: J
authors.lastname: Christophe
authors.forename: G
authors.initials: G
authors.lastname: Vantrappen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002266:Carboxymethylcellulose Sodium; D002415:Cats; D002845:Chromatography; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D004386:Duodenum / Q000737:chemistry; D005260:Female; D007082:Ileum / Q000737:chemistry; D007421:Intestine, Small / Q000737:chemistry*; D007583:Jejunum / Q000737:chemistry; D008297:Male; D008969:Molecular Sequence Data; D009037:Motilin / Q000302:isolation & purification*; D017386:Sequence Homology, Amino Acid
chemical_list: D009037:Motilin; D002266:Carboxymethylcellulose Sodium