Structure-activity studies on prolactin-releasing peptide (PrRP). Analogues of PrRP-(19-31)-peptide

An investigation of a series of single replacement analogues of PrRP-(19-31)-peptide has shown that good functional activity was retained when Phe(31) was replaced with His(Bzl), Phe(4Cl), Nle, Trp, Cys(Bzl) or Glu(OBzl); when Val(28) or Ile(25) was replaced with Phg; when Gly(24) was replaced with D-Ala, L-Ala, Pro or Sar; when Ser(22) was replaced with Gly and when Ala(21) was replaced with Thr or MeAla. The results confirm that the functionally important residues are located within the carboxyl terminal segment, -Ile-Arg-Pro-Val-Gly-Arg-Phe-NH2. Copyright (c) 2004 European Peptide Society and John Wiley & Sons, Ltd.