The effect of VIP on guinea pig taenia coli requires the whole sequence.
Truncated sequences of VIP1-28 i.e., VIP1-6, VIP15-28 and VIP18-28, were synthesized. The biological activity of the peptides was tested on the isolated taenia coli from guinea-pig. Unlike VIP1-28, the truncated peptides had no effect alone or in combination. We also synthesized two peptides where VIP1-6 or VIP1-9 were joined with VIP20-28 or VIP21-28, respectively, with omission of the mid portion of VIP1-28. These peptides had no detectable biological activity. Finally, we synthesized Gly17,18,19-VIP, and tested it in the above mentioned system. It had a greatly reduced bioactivity compared with native VIP.
D000595:Amino Acid Sequence; D000818:Animals; D003106:Colon / Q000187:drug effects / Q000502:physiology*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014660:Vasoactive Intestinal Peptide / Q000138:chemical synthesis / Q000494:pharmacology*
D010446:Peptide Fragments; D014660:Vasoactive Intestinal Peptide