Endosulfine, endogenous ligand for the sulphonylurea receptor: isolation from porcine brain and partial structural determination of the alpha form

Diabetologia. 1996 Feb;39(2):135-41. doi: 10.1007/BF00403955.


Anti-diabetic sulphonylureas act via high affinity binding sites coupled to K-ATP channels. Endosulfine, an endogenous ligand for these binding sites, was shown to exist in two molecular forms, alpha and beta, in both the pancreas and the central nervous system. We describe here the isolation, and partial structural characterization of alpha endosulfine derived from porcine brains by means of a series of chromatography runs and gel electrophoresis. Porcine alpha endosulfine is a protein with a molecular mass of 13,196 daltons as determined by mass spectrometry and which is N-terminally blocked. Tryptic digestion followed by separation of the fragments by HPLC and automated Edman degradation yielded a total of 72 amino acids in four partial sequences. Comparison of these sequences with that present in the National Biomedical Research Foundation protein data bank indicated a 82% identity with a 112-amino acid protein with a molecular mass of 12,353 daltons called "cyclic AMP-regulated phosphoprotein-19', isolated from the bovine brain as a substrate for protein kinase A.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters*
  • Amino Acid Sequence
  • Animals
  • Brain / metabolism
  • Cattle
  • Chromatography, Gel
  • Chromatography, High Pressure Liquid
  • Chromatography, Ion Exchange
  • Drosophila Proteins*
  • Electrophoresis, Polyacrylamide Gel
  • Intercellular Signaling Peptides and Proteins
  • Molecular Sequence Data
  • Molecular Weight
  • Peptide Fragments / chemistry
  • Peptide Fragments / isolation & purification
  • Peptides / chemistry*
  • Peptides / isolation & purification*
  • Peptides / metabolism
  • Phosphoproteins / chemistry
  • Potassium Channels / metabolism
  • Potassium Channels, Inwardly Rectifying*
  • Receptors, Drug / metabolism
  • Sequence Homology, Amino Acid
  • Sulfonylurea Receptors
  • Swine
  • Trypsin


  • ATP-Binding Cassette Transporters
  • Drosophila Proteins
  • Intercellular Signaling Peptides and Proteins
  • Peptide Fragments
  • Peptides
  • Phosphoproteins
  • Potassium Channels
  • Potassium Channels, Inwardly Rectifying
  • Receptors, Drug
  • Sulfonylurea Receptors
  • cyclic AMP-regulated phosphoprotein 19
  • endos protein, Drosophila
  • endosulfine
  • Trypsin

Associated data