The complete amino acid sequence of porcine gastrotropin, an ileal protein which stimulates gastric acid and pepsinogen secretion.
The stomach is stimulated by an enterooxyntin factor in a delayed response to feeding, resulting in an increase in both gastric acid and pepsinogen secretion. We have previously reported on the identity of such a factor from the porcine ileum (Wider, M. D., Vinik, A. I., and Heldsinger, A. (1984) Endocrinology 115, 1484-1491). This protein, termed gastrotropin, is localized to the distal region of the ileum where it constitutes less than 0.1% of the cytosolic protein. We have completed the primary structure of porcine gastrotropin by Edman degradation and mass spectrometry. Gastrotropin (Mr = 14,054) contains 127 amino acid residues and has a blocked (acetylated) alanine at its NH2 terminus. The sequence of porcine gastrotropin is similar to rat liver fatty acid-binding protein (FABP), with 44 of 127 residues being identical (35%). Homology with other members of the FABP family is significantly less apparent, with the order of similarity being liver FABP greater than heart FABP greater than retinol-binding protein greater than intestine FABP. The sequences of the NH2-terminal regions of these proteins account for virtually all of the homology; there are 9 conserved residues common to all five proteins. Gastrotropin represents the first member of the FABP family which has an extracellular function.
D000595:Amino Acid Sequence; D000818:Animals; D003488:Cyanogen Bromide; D050556:Fatty Acid-Binding Proteins; D005744:Gastric Acid / Q000378:metabolism*; D005768:Gastrointestinal Hormones / Q000302:isolation & purification* / Q000502:physiology; D007082:Ileum / Q000502:physiology*; D007413:Intestinal Mucosa / Q000502:physiology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010435:Pepsinogens / Q000378:metabolism*; D010446:Peptide Fragments / Q000302:isolation & purification; D010447:Peptide Hydrolases; D013552:Swine
D050556:Fatty Acid-Binding Proteins; D005768:Gastrointestinal Hormones; D010435:Pepsinogens; D010446:Peptide Fragments; C057275:fatty acid-binding protein 6; D010447:Peptide Hydrolases; D003488:Cyanogen Bromide