Solution structure of vaso-active intestinal polypeptide (11-28)-NH2, a fragment with analgesic properties

K. Haghjoo, P. W. Cash, R. S. Farid, B. R. Komisaruk, F. Jordan, S. S. Pochapsky

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9 Scopus citations


An 18-residue-long fragment ofvasoactive intestinal polypeptide [VIP(11-28)-NH2] that is known to be analgesic was synthesized by solid-phase t-Boc methodology on a 4-methylbenzhydrylamine resin. Circular dichroism spectroscopy gave evidence that the peptide acquires about 60% helical structure in 50/50 methanol/phosphate buffer, pH 6.0, and 65% (+5%) helicity in 80/20 methanol/phosphate buffer. pH 7.0. A 2.0 mM solution of VIP(1128)-NH2 in 80% methanol, 20% phosphate buffer pH 7.0 was subjected to 2-dimensional nuclear magnetic resonance (NMR) studies. The NMR results suggested formation of an extended helical structure extending from residue 11 to 27, essentially the same region found to be helical in a VIP(1-28)-NH2 analog. This finding suggests that the sequence required for analgesia assumes a helical structure at the receptor.

Original languageAmerican English
Pages (from-to)327-331
Number of pages5
JournalPeptide research
Issue number6
StatePublished - 1996

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology

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