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)

The heptacosapeptide amide corresponding to the entire amino acid sequence of chicken gastrin-releasing peptide (cGRP) was synthesized similarly to the synthesis of porcine GRP by assembling six peptide fragments followed by deprotection with 1 M trifluoromethanesulfonic acid-thioanisole in TFA. A new carboxyl-activating reagent, thiazolidine-2-thione, was preferentially adopted for preparation of necessary fragments. The synthetic cGRP, purified by ion-exchange chromatography, followed by partition chromatography, was active as the synthetic porcine GRP, when plasma immunoreactive gastrin level was examined in rats. No obvious difference was observed when synthetic and natural cGRP preparations were compared by HPLC, immunochemical property and biological activity in dogs.
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PMID:Studies on peptides. CXI. Synthesis of chicken gastrin-releasing peptide. 712 60

Cionin, a protochordate-derived octapeptide amide related to the gastrin/cholecystokinin family of peptides, contains two consecutive tyrosine sulfate residues. In order to gain insight into the role of the respective tyrosine sulfate residue in biological activity, cionin and its derivatives in which one of the two tyrosine sulfate residues was replaced by tyrosine, were prepared by two Fmoc-based solid-phase approaches. In approach (1) Fmoc-Tyr(SO3Na)-OH was employed as a building block to assemble the Tyr(SO3Na)-containing peptide-resin, and a global deprotection/cleavage was conducted with 90% aqueous TFA in the presence of m-cresol and 2-methylindole at 4 degrees C. In approach (2) the Tyr(Msib) [Msib = p-(methylsulfinyl)benzyl] derivative was used for the peptide-chain assembly to achieve sulfation on the selective Tyr residue. Partially protected peptide with the Msib/Msz protecting groups [Msz = p-(methylsulfinyl)benzyloxycarbonyl], obtained after peptide-resin cleavage, was treated with DMF-SO3 complex in the presence of ethanedithiol to achieve the sulfation of free Tyr residue and the reduction of the Msib/Msz groups to TFA-labile Mtb/Mtz groups [Mtb = p-(methylthio)benzyl, Mtz = p-(methylthio)benzyloxycarbonyl]. Final deprotection of the Mtb/Mtz groups with 90% aqueous TFA in the presence of m-cresol and 2-methylindole gave the desired cionin derivative, which contains the tyrosine sulfate residue at the selective position. Yields obtained with approach (2) were considerably higher than those obtained with approach (1). Cionin and mono-Tyr(SO3H)-containing derivatives were assayed on exocrine pancreas in dogs.
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PMID:Solid-phase synthesis of cionin, a protochordate-derived octapeptide related to the gastrin/cholecystokinin family of peptides, and its mono-tyrosine-sulfate-containing derivatives. 820 Jul 39

Radioimmunoassay has made it possible to measure the levels of many hormones. However, samples for some hormones, such as cholecystokinin (CCK), need to be purified by reverse phase chromatography before assay. Usually, samples are eluted from cartridges or HPLC columns in about 50% acetonitrile, dried on a vacuum centrifuge, and then reconstituted in buffer. Drying and reconstituting samples is time consuming and introduces additional sources of error and peptide loss. The present study investigated the effect of acetonitrile on radioimmunoassays for CCK to see if samples containing acetonitrile could be assayed directly. The non-specific binding of a radiolabeled peptide, the zero binding (B0), and the fall in the presence of 2.5 fmol unlabeled CCK were determined in the presence of various proportions of acetonitrile with 0.1% TFA. Additionally, standard curves were compared in the presence and absence of 200microl of 50% acetonitrile, (n = 5). For assays using two separate CCK antisera, increasing amounts of acetonitrile gave progressively higher zero binding and fall, thereby increasing sensitivity and antibody titer. The use of 200microl 50% acetonitrile, chosen to represent typical sample conditions, increased antiserum titers by three to four-fold, as well as increasing sensitivity considerably. For one antiserum (CCK2), the IC20 was 0.36+/-0.02 fmol CCK/tube in the presence of acetonitrile and 1.45+/-0.08 fmol/tube in its absence (P< 0.001). For the other antiserum (Dino 7), the IC20 was 0.40+/-0.02 fmol CCK/tube in the presence of acetonitrile and 0.63+/-0.01 fmol/tube in its absence (P<0.001). A similar increase in sensitivity was seen with a gastrin assay. However, no significant change in the gastrin antibody titer was evident. Assays for several other hormones were unaffected by 200 microl of 50% acetonitrile. At volumes encountered in samples following chromatography, acetonitrile did not adversely affect radioimmunoassays for a number of hormones, and the sensitivity and antibody titer of the CCK assays were improved. Measurement of CCK samples without drying and reconstitution increases assay efficiency and sensitivity.
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PMID:Radioimmunoassay of regulatory peptides in the presence of acetonitrile: marked improvement of cholecystokinin assays. 971 67

Chemical synthesis of tyrosine O-sulfated peptides is still a laborious task for peptide chemists because of the intrinsic acid-lability of the sulfate moiety. An efficient cleavage/deprotection procedure without loss of the sulfate is the critical difficulty remaining to be solved for fluoren-9-ylmethoxycarbonyl (Fmoc)-based solid-phase synthesis of sulfated peptides. To overcome the difficulty, TFA-mediated solvolysis rates of a tyrosine O-sulfate [Tyr(SO3H)] residue and two protecting groups, tBu for the hydroxyl group of Ser and 2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl (Pbf) for the guanidino group of Arg, were examined in detail. The desulfation obeyed first-order kinetics with a large entropy (59.6 J.K-1.mol-1) and enthalpy (110.5 kJ.mol-1) of activation. These values substantiated that the desulfation rate of the rigidly solvated Tyr(SO3H) residue was strongly temperature-dependent. By contrast, the SN1-type deprotections were less temperature-dependent and proceeded smoothly in TFA of a high ionizing power. Based on the large rate difference between the desulfation and the SN1-type deprotections in cold TFA, an efficient deprotection protocol for the sulfated peptides was developed. Our synthetic strategy for Tyr(SO3H)-containing peptides with this effective deprotection protocol is as follows: (i) a sulfated peptide chain is directly constructed on 2-chlorotrityl resin with Fmoc-based solid-phase chemistry using Fmoc-Tyr(SO3Na)-OH as a building block; (ii) the protected peptide-resin is treated with 90% aqueous TFA at 0 degree C for an appropriate period of time for the cleavage and deprotection. Human cholecystokinin (CCK)-12, mini gastrin-II (14 residues), and little gastrin-II (17 residues) were synthesized with this method in 26-38% yields without any difficulties. This method was further applied to the stepwise synthesis of human big gastrin-II (34 residues), CCK-33 and -39. Despite the prolonged acid treatment (15-18 h at 0 degree C), the ratios of the desulfated peptides were less than 15%, and the pure sulfated peptides were obtained in around 10% yields.
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PMID:Facile solid-phase synthesis of sulfated tyrosine-containing peptides: total synthesis of human big gastrin-II and cholecystokinin (CCK)-39. 1142 84

Application of the fluoren-9-ylmethoxycarbonyl (Fmoc)-based solid-phase segment condensation approach to the preparation of sulfated peptides was investigated through the synthesis of human big gastrin-II, a 34-residue sulfated tyrosine [Tyr(SO3H)]-containing peptide. Highly acid-sensitive 2-chlorotrityl resin (Clt resin) was exclusively employed as an anchor-resin for the preparation of the three peptide segments having the C-terminal Pro residue as well as of the Tyr(SO3H)-containing resin-bound segment. By using the PyBOP-mediated coupling protocol [PyBOP=benzotriazolyloxytris(pyrrolidino)phosphonium hexafluorophosphatel, we successively condensed each segment and constructed the 34-residue peptide-resin without any difficulty. The final acid treatment of the fully protected peptide-resin at low temperature (90% aqueous TFA, 0 degree C for 8 h), which can detach a Tyr(SO3H)-containing peptide from the resin and remove the protecting groups concurrently with minimum deterioration of the sulfate, afforded a crude sulfated peptide. After one-step HPLC purification, a highly homogeneous human big gastrin-II was easily obtained in 14% yield from the protected peptide-resin. The sulfate form of the C-terminal glycine-extended gastrin (G34-Gly sulfate), a posttranslational processing intermediate of gastrin-II, was also successfully prepared with the segment condensation approach (11% yield). These results demonstrated the usefulness of the segment condensation protocol for preparing large Tyr(SO3H)-containing peptides.
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PMID:Facile solid-phase synthesis of sulfated tyrosine-containing peptides: Part II. Total synthesis of human big gastrin-II and its C-terminal glycine-extended peptide (G34-Gly sulfate) by the solid-phase segment condensation approach. 1151 85