Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have isolated 2 clones encoding gastrin from a canine antral mucosa cDNA library. The clones differed in nucleotide sequence at 2 sites in the coding region. One of the clones confirmed the amino acid sequence of dog gastrin obtained by peptide purification and analysis. An A-G substitution in the other clone resulted in a Thr-Ala substitution in the region encoding the biologically active carboxyl-terminal portion of gastrin. The source of the observed heterogeneity in cDNA sequences is not known but its location may have implications with regard to the physiology of gastrin in dogs.
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PMID:Cloning of canine gastrin cDNA's encoding variant amino acid sequences. 226 79

We have previously demonstrated that the peptide Boc-L-Trp-L-Leu-beta-Ala is a potent and specific antagonist of pentagastrin-stimulated acid secretion in both the rat and the dog. Using conventional solution phase methodology, the analogue biotinyl-L-Trp-L-Leu-beta-Ala was prepared in reasonable yield and purity and applied to cryostat sections of rat intestinal and other tissues. The sections were exposed to 5-10 micrograms of peptide and the bound analogue was visualised using streptavidin-fluorescein. The binding of the analogue was demonstrated in sections from fundus, duodenum, ileum, colon, and lung. However, the analogue failed to bind to tissue from the pancreas, heart, kidney, or liver. The binding of the probe was greatly reduced or completely inhibited by preincubation with Boc-L-Trp-L-Leu-beta-Ala, pentagastrin, or gastrin 1-17. The distribution of the cells recognised by the probe was consistent with the distribution of histamine-containing enterochromaffin-like cells. The results of this study may have some bearing on current theories of the mechanism of gastrin-stimulated acid release.
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PMID:Visualisation of the gastrin receptor within rat mucosa using a biotinylated gastrin antagonist. 234 52

An approach to the solid-phase segment condensation synthesis of the 17-peptide amide human gastrin-I has been developed. N alpha-amino and side-chain protection were provided by 9-fluorenylmethyloxycarbonyl (Fmoc) and tert.-butyl groups, and a series of anchors cleavable under mild conditions were used. The N-terminal pentapeptide pGlu-Gly-Pro-Trp-Leu-OH was prepared using a p-alkoxybenzyl ester linkage made by a preformed handle strategy. Cleavage, in 65% yield, was with the new Reagent M: CF3COOH-CH2Cl2-beta-mercaptoethanol--anisole (70:30:2:1), which was optimized to preserve the labile tryptophan residue. A new preformed handle procedure expedited solid-phase synthesis of the protected "middle" hexapeptide, Fmoc-(Glu(OtBu]5-Ala-OH, anchored as an o-nitrobenzyl ester. Chains were not lost during this assembly, and final photolytic cleavage (350 nm) in toluene--CF3CH2OH (4:1) occurred in 59% yield. Both protected intermediates were purified by simple gel filtration, whereupon they were shown to be pure by analytical HPLC, and gave satisfactory NMR and FABMS spectra. Last, the C-terminal hexapeptide, Tyr(tBu)-Gly-Trp-Met-Asp(OtBu)-Phe, was assembled on a tris(alkoxy)benzylamide "PAL" support. For the polymer-supported segment condensation, the middle and N-terminal pieces were added respectively in greater than 98% and 89% yields (judged by amino acid analysis and solid-phase sequencing), by overnight couplings in N,N-dimethylformamide (DMF) mediated by benzotriazolyl N-oxytrisdimethylaminophosphonium hexafluorophosphate (BOP) in the presence of 1-hydroxybenzotriazole (HOBt) and N-methylmorpholine (NMM). Racemization was 4% and 11% respectively at Ala and Leu. Cleavage with Reagent M followed by reversed-phase chromatography gave pure gastrin-I in an overall 30% isolated yield. These results compare favorably with those from a stepwise assembly.
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PMID:Orthogonal solid-phase synthesis of human gastrin-I under mild conditions. 240 94

The effects on pancreatic responses of highly potent cyclic hexapeptide (cyclo (N-Me-Ala-Phe-D-Trp-Lys-Thr-Phe)) (Veber analog) and octapeptide analogs of somatostatin such as D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-ol (SMS 201-995), D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (RC-121), and D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) have been compared with somatostatin tetradecapeptide (SS-14) and atropine. The parameters evaluated were pancreatic responses to secretin and meat feeding in conscious dogs with chronic pancreatic fistula and amylase release from the dispersed pancreatic acini. The analogs were administered intravenously or intraduodenally. The cyclic hexapeptide and octapeptide analogs, given iv in graded doses against a constant background stimulation with secretin, produced similar and dose-dependent inhibition of pancreatic HCO3- and protein secretion. Analogs RC-121, RC-160, and the Veber analog were about two to four times more active than SS-14 in suppressing HCO3- secretion and equipotent in reducing protein secretion, but SMS 201-995 was only about half as potent as somatostatin in inhibiting HCO3-. RC-160 was effective in inhibiting secretin-induced protein secretion at lower doses than other analogs. In tests with feeding, SMS 201-995, the Veber analog, RC-121, and RC-160 were more potent inhibitors of exocrine pancreatic secretion of HCO3- and protein and exhibited more prolonged inhibitory effects than SS-14. The Veber analog, RC-121, and RC-160 were also more effective after intraduodenal administration. Atropine also caused significant inhibition of both HCO3- and protein responses to secretin and meal feeding. All four analogs decreased the postprandial insulin and pancreatic polypeptide release to a similar degree as SS-14. Neither SS-14 nor the analogs tested significantly affected basal or caerulein-, gastrin-, secretin-, or bethanechol-stimulated amylase release from the dispersed canine pancreatic acini. Atropine reduced amylase release induced by bethanechol, but not that stimulated by caerulein, gastrin, or secretin. This indicated that the analogs, as somatostatin, are ineffective as secretory inhibitors in vitro. We conclude that cyclic hexapeptide and octapeptide analogs are more potent and longer acting inhibitors of pancreatic secretion than somatostatin-14 in vivo.
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PMID:Comparison of somatostatin and its highly potent hexa- and octapeptide analogs on exocrine and endocrine pancreatic secretion. 244 2

The sulfakinins constitute a family of real and putative peptide sequences characterized from the cockroach Leucophaea maderae (leucosulfakinin subfamily) and fruitfly Drosophila melanogaster (drosulfakinin subfamily) with homology to the sulfated mammalian hormones gastrin II and cholecystokinin (CCK). The leucosulfakinin (LSK) subfamily of neuropeptides stimulate contractions of the isolated cockroach hindgut. In this paper, we have ascertained some of the primary structural requirements of the sulfakinins for myotropic (muscle-contracting) activity. The myotropic "active core" of this family has been determined to be the C-terminal hexapeptide, though the C-terminal octapeptide (Glu-Asp-Tyr(SO3H)-Gly-His-Met-Arg-Phe-NH2) is required for full activity. The LSKs demonstrate considerable tolerance to Ala substitution in positions 7 and 9 within the active core without complete loss of activity. Conversely, Ala substitution in positions 8, 10 and 11 led to inactive compounds. Basicity is a critical feature of LSK position 10, while aromatic character is an important characteristic for positions 8 and 11 for myotropic activity. Only trace activity could be observed upon replacement of the Tyr(SO3H) residue in LSK-position 6 with a Ser(SO3H). One analog ([3MeHis8] LSK) proved more active as a contractile stimulant than the natural product, while another ([7-11,Tyr(SO3H)7] LSK), conversely, demonstrated inhibition of spontaneous contractions of the cockroach hindgut.
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PMID:Structure-activity relationships for myotropic activity of the gastrin/cholecystokinin-like insect sulfakinins. 252 Jul 54

COOH-terminal decapeptide of gastrin-releasing peptide (GRP-10) is a bombesin-like peptide, which has bioactivities to stimulate gastrin, insulin, and glucagon secretion. We have synthesized an analogue of GRP-10 that inhibits GRP-10's stimulation of insulin secretion both in vivo and in vitro and glucagon secretion in vivo, while potentiating the stimulation of gastrin secretion. The amino acid sequence of this peptide is H-Gly-Asn-Trp-Ala-Ala-Gly-His-Leu-Met-NH2 ([Ala6]GRP-10). Because the stimulation of insulin and gastrin secretion by GRP-10 has been ascribed to a direct effect on B- and G-cells, these findings suggest that there are two subtypes of receptors for bombesin-like peptides in mammalian tissues.
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PMID:[Ala6]gastrin-releasing peptide-10: an analogue with dissociated biological activities. 266 16

SMS 201-995 is an octapeptide analogue of somatostatin. The effect of a single subcutaneous (s.c.) injection of 50 micrograms SMS 201-995 on post-prandial intermediary metabolism was investigated in normal subjects. In spite of a long-lasting post-prandial suppression of insulin secretion, there were no significant changes in the plasma concentration of alanine, glycerol, 3-OH-butyrate or lactate. However, SMS 201-995 impairs carbohydrate tolerance, probably due to inhibition of insulin secretion. Basal and post-prandial plasma concentrations of the gut regulatory peptides pancreatic glucagon, motilin, pancreatic polypeptide, gastric inhibitory polypeptide, enteroglucagon, gastrin and peptide YY were suppressed up to 5 hours after subcutaneous administration of a single dose of SMS 201-995.
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PMID:The effect of a long-acting somatostatin analogue (SMS 201-995) on intermediary metabolism and gut hormones after a test meal in normal subjects. 297 76

A dipeptidyl carboxypeptidase, which cleaved the Gly3-Phe4 bond of enkephalins, was purified from guinea pig serum 420-fold. The optimum pH of the enzyme was in the neutral range (pH 7.25), and the molecular weight was estimated to be approx. 280,000. The enzyme hydrolyzed Met- and Leu-enkephalin with Km values of 0.30 and 0.50 mM, respectively. The enzyme was inhibited by metal chelators and p-chloro-mercuribenzoate. Captopril showed high inhibitory potency, while phosphoramidon and Phe-Ala showed no effect on the enzyme activity. Therefore, the obtained enzyme can be classified as an angiotensin-converting enzyme (EC 3.4.15.1). Among the bioactive peptides examined, bradykinin and angiotensin I were hydrolyzed by the enzyme. Angiotensin III showed a stronger inhibitory effect than that of angiotensin II. Substance P, gastrin I, and secretin were also inhibitory toward the enzyme activity. On high-performance liquid chromatography analysis, Met-enkephalin-Arg6-Phe7 and Leu-enkephalin-Arg6 were cleaved sequentially at the second peptide bond of the C terminus. Thus, the dipeptidyl carboxypeptidase in guinea pig serum may play a role not only in the angiotensin-bradykinin system but also in the metabolism of circulating enkephalins and other bioactive peptides.
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PMID:Enkephalin-degrading dipeptidyl carboxypeptidase in guinea pig serum: its properties and action on bioactive peptides. 299 Mar 46

Deletion of residues 305 to 327 of polyomavirus middle T antigen, including the (Glu)6-Tyr-315 sequence that is a preferred site of phosphorylation in vitro by pp60c-src, markedly altered viral transformation of rat cells. The efficiency of transformation by the deletion mutant depended on how it was introduced into cells, and the resulting transformants displayed limited growth rates in monolayer and in suspension. Substitution of the polyomavirus residues 305 to 327 with a homologous region (containing [Glu]5-Ala-Tyr) from porcine gastrin did not restore wild-type transforming activity. These mutant middle T antigens interacted with pp60c-src and were phosphorylated in vitro. Thus, although a sequence of consecutive glutamic acid residues followed by a tyrosine is a dominant structural element which strongly influences the physical properties of middle T antigen, its presence did not ensure the biological activity of the protein. Other elements in this region of middle T antigen also contributed substantially to the transforming capacity of polyomavirus.
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PMID:Significance of the gastrin homology and surrounding sequences in polyomavirus middle T antigen for cell transformation. 300 48

Fasting metabolite and hormonal levels were studied prospectively in pancreatectomized dogs who had received grafts of their own pancreas. The results were compared with similarly diabetic animals who received exogenous insulin pumped intravenously either peripherally or portally. All animals were studied for 48-91 wk after pancreatectomy. In the autotransplanted animals, the fasting levels of glucose, lactate, pyruvate, alanine, pancreatic glucagon, insulin, gastric inhibitory peptide, and pancreatic polypeptide were all abnormal. In the peripherally infused animals, the fasting levels of glucose, pyruvate, alanine, free fatty acids, and insulin were also abnormal. In the portally infused animals, pyruvate, alanine, gastric inhibitory peptide, gastrin, and pancreatic polypeptide were abnormal. These results suggest that the portal route of insulin delivery may be necessary if fasting metabolite and hormonal levels are to approximate normal most closely whether exogenous intravenous insulin is replaced by implanted pumps or endogenous insulin is replaced by pancreatic transplants.
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PMID:Metabolic control in diabetic dogs treated with pancreatic autotransplants and insulin pumps. 307 15


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