Isolation of a neuropeptide from locust corpus cardiacum which influences ileal transport.
1. Schistocerca gregaria ion-transport peptide (Scg-ITP) was isolated from aqueous extracts of the corpus cardiacum by a four-step procedure, utilizing reverse-phase high-performance liquid chromatography for separation and stimulation of a Cl(-)-dependent short-circuit current (Isc) across locust ilea as the bioassay. 2. Scg-ITP has an unblocked N terminus and an apparent relative molecular mass of 7700. Thirty-one residues (of an estimated 65) were identified by sequence analysis. 3. Scg-ITP is structurally related to a crustacean family of neuropeptides which includes the crustacean hyperglycaemic hormones from the shore crab Carcinus maenas and the crayfish Orconectes limosus and moult-inhibiting hormone and vitellogenesis-inhibiting hormone from the lobster Homarus americanus. 4. Scg-ITP has no sequence homology with neuroparsins (Nps). Nps are the only other neuropeptides isolated to date that might regulate reabsorption in an insect hindgut (rectum).
Audsley
N
N
Department of Zoology, University of British Columbia, Vancouver, Canada.
McIntosh
C
C
Phillips
J E
JE
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006110:Grasshoppers; D007082:Ileum / Q000187:drug effects / Q000378:metabolism; D019476:Insect Proteins; D007408:Intestinal Absorption / Q000187:drug effects*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D009490:Neurosecretory Systems / Q000737:chemistry*
D000596:Amino Acids; D002352:Carrier Proteins; D019476:Insect Proteins; D009479:Neuropeptides; C079361:ion-transport peptide, Schistocerca gregaria