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Title: Identification of a gastrin binding protein in porcine gastric mucosal membranes by covalent cross-linking with iodinated gastrin

Abstract

A gastrin binding protein (GBP) has been identified in detergent extracts of porcine gastric mucosal membranes by covalent cross-linking to /sup 125/I-(Nle15)gastrin with disuccinimidyl suberate. The apparent molecular weight of the cross-linked complex (80,000) is uneffected by reduction suggesting that the GBP is not composed of disulfide-bonded subunits. Subtraction of the molecular weight of 125I-gastrin indicates that the molecular weight of the GBP is 78,000. A similar molecular weight has been observed previously for the gastrin receptor (74,000) on intact canine parietal cells and plasma membranes therefrom, and for the receptor for the related hormone cholecystokinin (76,000-85,000) on pancreatic acinar membranes under reducing conditions. The similarity in molecular weight between the gastrin receptor and the solubilized GBP suggests that the latter protein is probably the gastrin receptor. However, the concentration (2 microM) of (Nle15)gastrin required for 50% inhibition of cross-linking of gastrin to the GBP solubilized in 0.1% Triton X-100 is 200-fold greater than the value (10 nM) observed for the gastrin receptor on isolated canine gastric parietal cells. A lower concentration (0.3 microM) of (Nle15)gastrin was required to inhibit cross-linking in a milder detergent (0.4% digitonin, 0.08% cholate). Thus, the reduced affinity for gastrin of the putative solubilized formmore » of the gastrin receptor appears to be a result of detergent extraction.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Ludwig Institute for Cancer Research, Victoria, Australia
OSTI Identifier:
5073446
Resource Type:
Journal Article
Journal Name:
J. Biol. Chem.; (United States)
Additional Journal Information:
Journal Volume: 26
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; GASTRIN; RADIORECEPTOR ASSAY; CELL MEMBRANES; DOGS; GUINEA PIGS; IODINE 125; LABELLED COMPOUNDS; METALS; MOLECULAR WEIGHT; PROTEINS; RABBITS; RATS; STOMACH; SWINE; TRACER TECHNIQUES; ANIMALS; BETA DECAY RADIOISOTOPES; BODY; CELL CONSTITUENTS; DAYS LIVING RADIOISOTOPES; DIGESTIVE SYSTEM; DOMESTIC ANIMALS; ELECTRON CAPTURE RADIOISOTOPES; ELEMENTS; GASTROINTESTINAL TRACT; HORMONES; INTERMEDIATE MASS NUCLEI; IODINE ISOTOPES; ISOTOPE APPLICATIONS; ISOTOPES; MAMMALS; MEMBRANES; NUCLEI; ODD-EVEN NUCLEI; ORGANIC COMPOUNDS; ORGANS; PEPTIDE HORMONES; PEPTIDES; POLYPEPTIDES; RADIOISOTOPES; RODENTS; VERTEBRATES; 550201* - Biochemistry- Tracer Techniques

Citation Formats

Baldwin, G.S., Chandler, R., Scanlon, D.B., and Weinstock, J. Identification of a gastrin binding protein in porcine gastric mucosal membranes by covalent cross-linking with iodinated gastrin. United States: N. p., 1986. Web.
Baldwin, G.S., Chandler, R., Scanlon, D.B., & Weinstock, J. Identification of a gastrin binding protein in porcine gastric mucosal membranes by covalent cross-linking with iodinated gastrin. United States.
Baldwin, G.S., Chandler, R., Scanlon, D.B., and Weinstock, J. Mon . "Identification of a gastrin binding protein in porcine gastric mucosal membranes by covalent cross-linking with iodinated gastrin". United States.
@article{osti_5073446,
title = {Identification of a gastrin binding protein in porcine gastric mucosal membranes by covalent cross-linking with iodinated gastrin},
author = {Baldwin, G.S. and Chandler, R. and Scanlon, D.B. and Weinstock, J.},
abstractNote = {A gastrin binding protein (GBP) has been identified in detergent extracts of porcine gastric mucosal membranes by covalent cross-linking to /sup 125/I-(Nle15)gastrin with disuccinimidyl suberate. The apparent molecular weight of the cross-linked complex (80,000) is uneffected by reduction suggesting that the GBP is not composed of disulfide-bonded subunits. Subtraction of the molecular weight of 125I-gastrin indicates that the molecular weight of the GBP is 78,000. A similar molecular weight has been observed previously for the gastrin receptor (74,000) on intact canine parietal cells and plasma membranes therefrom, and for the receptor for the related hormone cholecystokinin (76,000-85,000) on pancreatic acinar membranes under reducing conditions. The similarity in molecular weight between the gastrin receptor and the solubilized GBP suggests that the latter protein is probably the gastrin receptor. However, the concentration (2 microM) of (Nle15)gastrin required for 50% inhibition of cross-linking of gastrin to the GBP solubilized in 0.1% Triton X-100 is 200-fold greater than the value (10 nM) observed for the gastrin receptor on isolated canine gastric parietal cells. A lower concentration (0.3 microM) of (Nle15)gastrin was required to inhibit cross-linking in a milder detergent (0.4% digitonin, 0.08% cholate). Thus, the reduced affinity for gastrin of the putative solubilized form of the gastrin receptor appears to be a result of detergent extraction.},
doi = {},
journal = {J. Biol. Chem.; (United States)},
number = ,
volume = 26,
place = {United States},
year = {1986},
month = {9}
}