Isolation and partial amino acid sequence of a 78 kDa porcine gastrin-binding protein.
1. A 78 kDa protein (p78) has been partially purified from washed membranes isolated from the corpus of porcine gastric mucosa. The purification was monitored by covalent cross-linking of iodinated [Nle15]-gastrin. 2. A single N-terminal sequence extending for 33 amino acids was obtained from the p78 preparation. Partial sequences totalling 192 amino acids were also obtained from 14 tryptic and 3 Staphylococcal V8 peptides. 3. 10 peptides plus the N-terminal sequence were derived from a previously unsequenced protein which was distantly related to the product of the E. coli fadB gene (Baldwin G. S. (1993) Comp. Biochem. Physiol. 104B, 55-61). The remaining 7 peptides were derived from the beta-subunit of the gastric H+/K(+)-ATPase. 4. The gastrin-binding activity remained in association with p78, and could be separated from the beta-subunit of the gastric H+/K(+)-ATPase, during chromatography on tomato lectin-Sepharose. 5. We conclude that p78 binds gastrin, and is a novel member of the enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase family of enzymes.
Ludwig Institute for Cancer Research, Melbourne Tumour Biology Branch, Royal Melbourne Hospital, Victoria, Australia.
G S
GS
Baldwin
R
R
Chandler
B
B
Grego
M R
MR
Rubira
K L
KL
Seet
J
J
Weinstock
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D004746:Enoyl-CoA Hydratase / Q000737:chemistry; D005753:Gastric Mucosa / Q000737:chemistry; D005755:Gastrins / Q000378:metabolism; D017506:H(+)-K(+)-Exchanging ATPase / Q000737:chemistry / Q000235:genetics; D063991:Mitochondrial Trifunctional Protein; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009097:Multienzyme Complexes; D010446:Peptide Fragments / Q000235:genetics / Q000302:isolation & purification; D013552:Swine
D002352:Carrier Proteins; D005755:Gastrins; D009097:Multienzyme Complexes; D010446:Peptide Fragments; D015094:3-Hydroxyacyl CoA Dehydrogenases; D063991:Mitochondrial Trifunctional Protein; D017506:H(+)-K(+)-Exchanging ATPase; D004746:Enoyl-CoA Hydratase