title: The synthesis of an analogue of the locust CRF-like diuretic peptide, and the biological activities of this and some C-terminal fragments.
abstract: The synthesis is described of an analogue of the locust CRF-like diuretic peptide in which methionine in positions 1,3, and 13 is replaced by isosteric methyl-homoserine residues. This analogue has been tested for biological activity on Malpighian tubules in vitro, and feeding behavior in vivo. It is highly active in stimulating fluid secretion and accumulation of cAMP in tubules, and on increasing the latency to feed and reducing meal duration. A 15 residue fragment from the C-terminus of the CRF-like peptide, Locmi-DP(32-46), is fully active in the feeding assay, but has only weak ability to stimulate the accumulation of cAMP in tubules. Two smaller fragments, Locmi-DP(32-37) and Locmi-DP(41-46), were tested but neither had consistent biological activity in any of the assays used here. None of the peptides tested have any substantive activity in increasing cGMP in tubules.
authors.affiliation: Department of Biology, Birkbeck College, University of London, Malet Street, WC1E 7HX, London, UK. g.goldsworthy@bbk.ac.uk
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Goldsworthy
authors.forename: J Sook
authors.initials: JS
authors.lastname: Chung
authors.forename: Monique S J
authors.initials: MS
authors.lastname: Simmonds
authors.forename: Maria
authors.initials: M
authors.lastname: Tatari
authors.forename: Sophia
authors.initials: S
authors.lastname: Varouni
authors.forename: Constantine P
authors.initials: CP
authors.lastname: Poulos
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D004232:Diuretics / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D005247:Feeding Behavior / Q000187:drug effects; D006110:Grasshoppers / Q000737:chemistry*; D066298:In Vitro Techniques; D007267:Injections; D019476:Insect Proteins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D008317:Malpighian Tubules / Q000187:drug effects; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004232:Diuretics; D019476:Insect Proteins; D010446:Peptide Fragments; D003346:Corticotropin-Releasing Hormone