Porcine motilin

Yamada S, Ikota N, Shioiri T. Diphenyl phosphorazidate (DPPA) and diethyl phosphorocyanidate (DEPC). Two new reagents for solid-phase peptide synthesis and their application to the synthesis of porcine motilin. J. Am. Chem. Soc. 1975 97 7174-7175. 

Ikota N, Shioiri T, Yamada S, Tachibana S. Amino acids and peptides. XXXI. Phosphorus in organic synthesis. XVIII. Synthesis of porcine motilin by the solid-phase method us- 41. ing diphenyl phosphorazidate (DPPA) and diethyl phosphoro-cyanidate (DEPC). Chem. Pharm. Bull. 1980 28 3347-5336. 

In order to construct porcine motilin,f l a protected nonapeptide corresponding to the sequence 14-22 of motilin was prepared in a stepwise elongation manner by the active ester method starting from C-terminal glutamine, as shown in Scheme... 

The rabbit intestinal segments showed rhythmic contractions superimposed on the basal tonus. Porcine motilin caused an increase in the basal tonus in a concentration-dependent manner without affecting the frequency of phasic contractions. The sensitivity of the response to motilin decreased aboradly the minimum effective concentrations for the duodenum, jejunum, and ileum were 1 x 10 , 3 X 10, and 1 x 10 M, respectively. The maximal contractile responses of the duodenum, jejunum, and ileum were 89%, 50%, and 11%, respectively. 

Fig. 6. Top Effects of (A) EM574 and (B) porcine motilin on gastrointestinal contractile activity in the interdigestive state in the conscious dog. Both agents induced IMC-like migrating contractions. Bottom Effect of cisapride on gastrointestinal contractile activity in the fasting dog [(A), 0.3 mg/kg (B), 1 mg/kg]. The contractile pattern of cisapride-evoked contractions was different from those induced by EM574 and motilin. (From Inatomi et al. [15] with permission of the editor.)...

Fig. 12. Effects of EM574, porcine motilin, and cisapride on gastric antral motility after a semisolid meal. The meal was ingested within 5 min. EM574 and cisapride were administered intraduode-nally immediately after feeding. Motilin was infused intravenously during 30-min postprandial period. A representative pattern of interdigestive migrating complex (IMC) is shown in the inset to indicate the magnitude of contractions. (From Sato et al. [22] with permission from Elsevier Science.)...

Fig. 14. Responses of isolated rabbit duodenum to acetylcholine, EM574, or porcine motilin. After supramaximal dosing of acetylcholine followed by washing out, EM574 or motilin was applied in cumnlative concentrations. EM574 and motilin produced an increase in the basal tonus of the segment in a dose-dependent manner. (From Sato et at [34] with permission from Elsevier Science.)...

Haramura, M., Tsusuki, K., Okamachi, A., Yogo, K., Ikuta, M., Kozono, T, Takanashi, H., and Murayama, E. (1999). Structure-activity study of intact porcine motilin. Chem. Pharm. Bull. 47, 1555-1559. 

Javet, J., Zdunek, J., Damberg, P, and Gaslund, A. (1997). Three-dimensional structure and position of porcine motilin in sodium dodecyl sulfate micelles determined by H-NMR. Biochemistry 36,8153-8163. 

Porcine motilin, which contains 22 amino adds, has been isolated from mucosa of hog small intestine J. C. Brown et al., Can, J. Physiol Pharmacol 49, 399 (1971). Purification, amino acid composition, C-terminal residue eidem. Gastroenterology 62, 401 (1972), Amino acid sequence eidem. 

Solid-phase peptide synthesis. Both diethyl phosphorocyanidate and the related diphenylphosphoryl azide have been shown to be useful in solid-phase peptide synthesis. They have been used successfully for synthesis of porcine motilin (composed of 22 amino acids). 

Motilin 55 (gastric motor activity-stimulating polypeptide), isolated from porcine intestine by Mutt and Brown 123), stimulates gastric motility and pepsin secretion. 

Fig. 15. Displacement studies with porcine (po.) motilin (+) and erythromycin A (O) and its derivatives EM502 ( ), EM523 (A), EM536 (A), and EM574 ( ). The binding displacement curves are almost parallel. Data are expressed as means SE of three to five experiments. (From Sato et al. [34] with permission from Elsevier Science.)...

Motilin (Mot), FVPIFTYGEL QRMQE KERNK GQ, a 22-peptide hormone belonging to the —r ghrelin family. MotUin stimulates the contraction of smooth muscle in the gastrointestinal tract. MotUin was originally isolated from porcine gut. 

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