Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been speculated that opiate tolerance and dependence may occur at the level of gene expression. Our previous studies have shown that the binding activity of a nuclear factor (ssCRE-BP) to single-stranded CRE of somatostatin gene is altered by long-term treatment with morphine in the mouse cerebellum. ssCRE-BP was purified from the mouse cerebellum by a combination of chromatography on DNA affinity agarose and Mono Q HR. The native protein exhibited a molecular size of 110-150 kDa by gel filtration, and two polypeptides of about 35-40 kDa were observed on SDS-PAGE. The cloning and sequencing of a cDNA encoding ssCRE-BP showed that the protein possesses a glycine-rich domain and a glutamine-rich domain in the amino terminus and the carboxyl terminus, respectively. To investigate the function of ssCRE-BP in the brain, recombinant glutathione-S-transferase (GST) fusion proteins containing ssCRE-BP were expressed in bacterial systems. Rabbit anti-ssCRE-BP antibodies were raised against a GST-ssCRE-BP fusion protein. Using the antibodies in western blot analysis, a polypeptide of approximately 66 kDa was detected in the brain. These findings indicate that ssCRE-BP is involved in opiate tolerance and dependence.
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PMID:Characterization of single-stranded cAMP response element binding protein (ssCRE-BP) from mouse cerebellum. 895 22

Due to persistent qualitative abnormalities in GH secretion following treatment, and lack of a sensitive marker of GHD in mid-adult life it is extremely difficult to diagnose GHD in treated acromegalic patients. The diagnosis of GHD in patients with pituitary disease relies on provocative tests of GH reserve. Arginine releases GH by reducing somatostatin inhibition of GH release, whereas GH secretagogues (GHS) affect GH release by direct stimulation of the GHS receptor, though an intact GH releasing hormone (GHRH) axis is a prerequisite. The peak GH response to insulin-induced hypoglycaemia and arginine in acromegalic patients, in whom basal serum GH levels of less than 5 mU/l have been achieved, is greatly diminished in those treated by hypothalamo-pituitary irradiation. We aimed to study the response of successfully treated acromegalic patients to the growth hormone secretagogue hexarelin in view of its different putative mechanism of action, and in addition, to determine whether it has any value in the diagnosis of GH deficiency in this subset of patients. Nineteen acromegalic patients, in whom mean serum GH levels below 5 mU/l have been achieved through treatment, were recruited. Eight of the patients had been treated by surgery alone (Group A) and 11 had received primary or postoperative irradiation (Group B). All patients underwent 20 min blood sampling to provide a 24-h GH profile. Serum IGF-I was measured from a sample drawn between 0900 h and 1000 h. On a second visit arginine 20 g/m2 was infused over 30 min, blood samples were taken before commencing the infusion and at 30-min intervals thereafter for 180 min. At the final visit hexarelin 1.5 mcg/kg was administered as an intravenous bolus at t = 0. Blood was drawn at 15-min intervals from - 30 to 180 min. All patients in group A showed an increment in serum GH following hexarelin (DeltaGHHEX) > 20 mU/l, a normal response to arginine, and a mean 24-h GH > 0.5 mU/l. In group B only 4/11 achieved a DeltaGHHEX > 20 mU/l, 5/11 producing a response of < 2 mU/l. Four of the five patients with a DeltaGHHEX < 2 mU/l were also demonstrated to have a mean 24-h GH of < 0.5 mU/l and serum IGF-I SDS < + 0.5. All four patients in Group B who achieved a DeltaGHHEX > 20 mU/l, were observed to show an absent or minimal GH response to arginine. Despite loss of the GH response to arginine, the DeltaGHHEX is retained in a proportion of those patients in whom "safe" GH levels were achieved following irradiation. From the putative mechanisms of action of these provocative agents a plausible explanation would be that the GHRH axis is more resilient than endogenous somatostatin-secreting neurones to radiation-induced damage. Furthermore, GH secretagogues may have a role, in combination with serum IGF-I levels, in the diagnosis of GH deficiency in treated acromegaly.
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PMID:The diagnosis of growth hormone deficiency (GHD) in successfully treated acromegalic patients. 1116 24

To construct the ss/HBsAg protein gene-engineering vaccine for developing the diagnosis and cure tumors in clinical medicine and promoting the growth in animal husbandry production. A pair of primers were designed according separately to the sequence of Somatostatin gene(S14) and HBsAg gene. Their gene fragments were separately amplified by using PCR and cloned, following sequencing, the DNA fragments were inserted into pBluescript vector. Then the ss/HBsAg chimera was constructed and was cloned into pPICZaA plasmid, and transformed into electroporated Pichia pastoris. High yield protein expression was obtained. Expressed protein was proved with high specificity and it's molecular weigh was about 28 KD identified by SDS-PAGE and Western blot.
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PMID:[Construction and expression of somatostatin (S14) and hepatitis B surface antigen gene in yeast Pichia pastoris]. 1255 29

Urotensin II (U-II) is a disulfide-bridged undecapeptide recently identified as the ligand of an orphan G-protein-coupled receptor. Human U-II (H-Glu-Thr-Pro-Asp-cyclo[Cys-Phe-Trp-Lys-Tyr-Cys]-Val-OH) has been described as the most potent vasoconstrictor compound identified to date. With the aim of elucidating the active conformation of hU-II, we have performed a spectroscopic analysis of hU-II minimal active fragment hU-II(4-11) in different environmental conditions. The analysis indicated that hU-II(4-11) was highly structured in the anisotropic membrane mimetic SDS solution, showing a type II' beta-turn structure, which is almost unprecedented for L-amino acid peptides. Micelle bound structure of hU-II(4-11) was then compared with those of four synthetic analogues recently synthesized in our lab, bearing modified Cys residues at position 5 and/or position 10 and characterized by different levels of agonist activity. The structures of the active compounds were found to be very similar to that of hU-II(4-11), while a barely active compound does not show any propensity to beta-turn formation. Furthermore, distances among putative pharmacophoric points in the structures of the active compounds obtained in SDS solution are in good agreement with those found in a recently described non-peptide agonist of the hU-II receptor. A type II' beta-turn structure was already found for the somatostatin analogue octreotide. On the basis of the similarity of the primary and 3D structures of U-II and somatostatin analogues and on the basis of the sequence homology between the GPR14/UT-II receptor and members of the somatostatin receptor family, a common evolutionary pathway for the signal transmission system activated by these peptide can be hypothesized.
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PMID:Unraveling the active conformation of urotensin II. 1502 56

GHRH stimulates GH secretion in chickens as in mammals. However, nothing is known about the chicken GHRH receptor (GHRH-R). Here we report the cDNA sequence of chicken GHRH-R. Comparison of the cDNA sequence with the chicken genome localized the GHRH-R gene to chicken chromosome 2 and indicated that the chicken GHRH-R gene consists of 13 exons. Expression of all exons was confirmed by RT-PCR amplification of pituitary mRNA. The amino acid sequence predicted by the GHRH-R cDNA is homologous to that in other vertebrates and contains seven transmembrane domains and a conserved hormone-binding domain. The predicted size of the GHRH-R protein (48.9 kDa) was confirmed by binding of (125)I-GHRH to chicken pituitary membranes and SDS-PAGE. GHRH-R mRNA was readily detected by RT-PCR in the pituitary but not in the hypothalamus, total brain, lung, adrenal, ovary, or pineal gland. Effects of corticosterone (CORT), GHRH, ghrelin, pituitary adenylate cyclase-activating peptide, somatostatin (SRIF), and TRH on GHRH-R and GH gene expression were determined in cultures of chicken anterior pituitary cells. GHRH-R and GH mRNA levels were determined by quantitative real-time RT-PCR. Whereas all treatments affected levels of GH mRNA, only CORT, GHRH, and SRIF significantly altered GHRH-R mRNA levels. GHRH-R gene expression was modestly increased by GHRH and suppressed by SRIF at 4 h, and CORT dramatically decreased levels of GHRH-R mRNA at 72 h. We conclude that adrenal glucocorticoids may substantially impact pituitary GH responses to GHRH in the chicken through modulation of GHRH-R gene expression.
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PMID:Identification of the chicken growth hormone-releasing hormone receptor (GHRH-R) mRNA and gene: regulation of anterior pituitary GHRH-R mRNA levels by homologous and heterologous hormones. 1646

The covalent conjugation of a functionalized poly(ethylene glycol) (PEG) to multiple nucleophilic amine residues results in a heterogeneous mixture of PEG positional isomers. Their physicochemical, biological, and pharmaceutical properties vary with the site of conjugation of PEG. Yields are low because of inefficient conjugation chemistry and production costs high because of complex purification procedures. Our solution to these fundamental problems in PEGylating proteins has been to exploit the latent conjugation selectivity of the two sulfur atoms that are derived from the ubiquitous disulfide bonds of proteins. This approach to PEGylation involves two steps: (1) disulfide reduction to release the two cysteine thiols and (2) re-forming the disulfide by bis-alkylation via a three-carbon bridge to which PEG was covalently attached. During this process, irreversible denaturation of the protein did not occur. Mechanistically, the conjugation is conducted by a sequential, interactive bis-alkylation using alpha,beta-unsaturated beta'-monosulfone functionalized PEG reagents. The combination of (a) maintaining the protein's tertiary structure after disulfide reduction, (b) the mechanism for bis-thiol selectivity of the PEG reagent, and (c) the steric shielding of PEG ensure that only one PEG molecule is conjugated at each disulfide bond. PEG was site-specifically conjugated via a three-carbon bridge to 2 equiv of the tripeptide glutathione, the cyclic peptide hormone somatostatin, the tetrameric protein l-asparaginase, and to the disulfides in interferon alpha-2b (IFN). SDS-PAGE, mass spectral, and NMR analyses were used to confirm conjugation, thiol selectivity, and connectivity. The biological activity of the l-asparaginase did not change after the attachment of four PEG molecules. In the case of IFN, a small reduction in biological activity was seen with the single-bridged IFN (without PEG attached). A significantly larger reduction in biological activity was seen with the three-carbon disulfide single-bridged PEG-IFNs and with the double-bridged IFN (without PEG attached). The reduction of the PEG-IFN's in vitro biological activity was a consequence of the steric shielding caused by PEG, and it was comparable to that seen with all other forms of PEG-IFNs reported. However, when a three-carbon bridge was used to attach PEG, our PEG-IFN's biological activity was found to be independent of the length of the PEG. This property has not previously been described for PEG-IFNs. Our studies therefore suggest that peptides, proteins, enzymes, and antibody fragments can be site-specifically PEGylated across a native disulfide bond using three-carbon bridges without destroying their tertiary structure or abolishing their biological activity. The stoichiometric efficiency of this approach also enables recycling of any unreacted protein. It therefore offers the potential to make PEGylated biopharmaceuticals as cost-effective medicines for global use.
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PMID:Site-specific PEGylation of protein disulfide bonds using a three-carbon bridge. 1722 58

In the current work, the fusion gene including somatostatin (SS) and the hepatitis B surface antigen gene was cloned into a balanced lethal system plasmid (pYA3493), and then transformed into asd- attenuated Salmonella choleraesuis C500 strain, the positive transformant without antibiotic resistance gene was confirmed by restriction analysis and DNA sequencing, designated as pYA-SS. The expression and immunogenicity of fusion protein were detected by SDS-PAGE and Western blot analysis. These results show that the recombinant prokaryotic expression plasmid pYA-SS could express the SS fusion protein with good immunogenicity in C500 strain. In above all, this study could provide reliable materials to develop novel, good and safe vaccine in enhancing the growth of animals.
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PMID:[Construction and characterization of a novel somatostatin prokaryotic expression]. 1880 81

Protein phosphorylation/dephosphorylation of tyrosine residues is an important regulatory mechanism in cell growth and differentiation. Previously it has been reported that RC-160, an octapeptide analog of somatostatin, and [D-Trp6]LHRH, an agonist of luteinizing hormone-releasing hormone (LHRH), stimulate receptor-mediated activity of tyrosine phosphatases (PTP) and reverse growth promotion of the tyrosine kinase (PTK) class of oncogenes in tumor cells. The effect of RC-160 and [D-Trp6]LHRH on protein phosphorylation was further examined in surgical specimens of human carcinomas. Protein extracts of human ovarian, liver, breast and prostate tumor samples were preincubated with epidermal growth factor (EGF) (10(-7) M) with or without [D-Trp6]LHRH or RC-160 (10(-6) M) at 25 degrees C for 2 h, followed by incubation for 10 min with [gamma-32p]ATP. SDS-PAGE, Western blotting, autoradiography and densitometry were then used to quantify the phosphorylation level of individual protein bands. It was found that EGF enhanced, and [D-Trp6]LHRH and RC-160 reduced phosphorylation of a prominent 300-kDa band. Two proteins (65 and 60 kDa), involved in growth control in tumor cell lines, were also identified in this study. The homology of substrate phosphorylation between induced PTK and PTP in the presence of hormones provided evidence that these substrates might be identical or related in tumors. These findings, along with the previous cell culture results, suggest that many solid tumors may respond to treatment with analogues of somatostatin and LHRH. Collectively, the results further support the hypothesis that these 60-, 65- and 300-kDa protein substrates may be involved in growth-message transduction.
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PMID:Dephosphorylation of cancer protein by tyrosine phosphatases in response to analogs of luteinizing hormone-releasing hormone and somatostatin. 1903 84

A limited set of novel octreotide dicarba-analogues with non-native aromatic side chains in positions 7 and/or 10 were synthesized. Their affinity toward the ssts1-5 was determined. Derivative 4 exhibited a pan-somatostatin activity, except sst4, and derivative 8 exhibited high affinity and selectivity toward sst5. Actually, compound 8 has similar sst5 affinity (IC50 4.9 nM) to SRIF-28 and octreotide. Structure-activity relationships suggest that the Z geometry of the double-bond bridge is that preferred by the receptors. The NMR study on the conformations of these compounds in SDS(-d25) micelles solution shows that all these analogues have the pharmacophore beta-turn spanning Xaa7-D-Trp8-Lys9-Yaa10 residues. Notably, the correlation between conformation families and affinity data strongly indicates that the sst5 selectivity is favored by a helical conformation involving the C-terminus triad, while a pan-SRIF mimic activity is based mainly on a conformational equilibrium between extended and folded conformational states.
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PMID:Novel octreotide dicarba-analogues with high affinity and different selectivity for somatostatin receptors. 2066 84

In order to obtain a virus-like particle vaccine both for porcine parvovirus (PPV) prevention and growth-promotion, VP2 gene of PPV NJ-a strain was amplified with PCR, and four copies of synthetic somatostatin gene were fused to the N-terminal of VP2 gene. The fused gene was cloned into pFast-HT A to construct the recombinant plasmid pFast-SS4-VP2, then the pFast-SS4-VP2 was transformed into DH10Bac competent cells and recombined with shuttle vector Bacmid, followed by identification with blue-white screening and PCR analysis for three cycles, and the positive recombinant was named as rBacmid-SS4-VP2. The positive Sf-9 cells were transfected with rBacmid-SS4-VP2 by Lipofectamine to produce recombinant baculovirus. When the cytopathic effect (CPE) was obvious, the transfected Sf-9 cell was harvested, and the positive recombinant virus was named as rBac-SS4-VP2. The insertion for the target gene into baculovirus genome was confirmed with PCR. SDS-PAGE and Western blotting revealed that the calculated protein of approximately 68 kDa was in the expressed in the insect cells. The Sf-9 cells infected with rBac-SS4-VP2 were stained positive against PPV antibody using the indirect immunofluorescence assay (IFA). Moreover, the virus particle self-assembly was observed under electron microscopy. 90 four-week-old mice were immunized by the recombinant protein coupled with different adjuvants alhydrogel, IMS and oil. VP2-specific ELISA antibodies, PPV-specific neutralizing antibody, somatostatin antibody and growth hormone levels were examined to evaluate the immunogenicity of this virus like particle. Results indicated that mice groups immunized rSS4-VP2 protein with alhydrogel and IMS developed similar humoral immune response comparing with inactived PPV vaccine. Mice group immunized with rSS4-VP2 generated higher level of SS antibody and growth hormone comparing with negative control, mice receiving rSS4-VP2 with alhydrogel developed the highest antibody titre than all other groups, while the oil group developed the lowest antibody level. This study provides not only a new rout for production of safe and effective virus like particle subunit vaccine, but also the foundations for peptide presentation and multivalent subunit vaccine design.
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PMID:[Construction and immunogenicity of recombinant porcine parvovirus-like particles with somatostatin]. 2109 Jan 9


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