Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The circular dichroic spectra of [Arg8]vasopressin, [Mpr1, Arg8]vasopressin, [Mpr1, D-Arg8]-vasopressin, pressinamide, deaminopressinamide, tocinamide, deaminotocinamide, [Leu4, D-Arg8]-vasotocin, [Mpr1, Leu4, D-Arg8]vasotocin and [Phe2, Lys8]vasopressin have been studied. All these substances showed a characteristic positive dichroic band at about 225 nm due to the presence of tyrosine in sequence position 2. The intensity of this band was affected by interactions between the tyrosine side-chain and other structural elements in the molecule, such as the Na-amino group, the side-chain of phenylalanine in position 3 and the linear C-terminal peptide. Analysis of the response of this band to structural modifications of the molecule and change in the solvent (particularly comparing neutral aqueous solutions with hexafluoroacetone solutions) allowed some conformational conclusions. The linear C-terminal tripeptide is probably situated over the cyclic portion of the molecule both in vasopressin and oxytocin substances. Its steric interaction with the tyrosine side-chain seems to be particularly efficient in molecules containing D-arginine in position 8. In the vasopressin series the stacking interaction of neighbouring aromatic amino acid residues furthermore limits the conformational freedom of the tyrosine side-chain and also probably distorts the dihedral angles of residues 1-3 in comparison with oxytocin. The interactions of phenylalanine and arginine with tyrosine relatively decrease the conformational effects of the primary amino group. Consequently the local conformation of vasopressin in the region of the tyrosine residue is more rigid and less sensitive to changes in medium than that of oxytocin. The circular dichroic spectra did not show any basic conformational differences in the backbone peptide chain of oxytocin and vasopressin substances. A weak negative disulphide band at about 290 nm could be observed in the spectra of both series of substances.
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PMID:Circular-dichroic spectra of vasopressin analogues and their cyclic fragments. 24 Jul 13

The homozygous Brattleboro rat (di/di), displaying a hypothalamic form of diabetes insipidus, synthesizes a vasopressin (VP) precursor with an abnormal C-terminus. The phenotypic expression of coexisting peptides in mutant magnocellular VP cells shows a differential pattern. 7B2 is one of the peptides which is not detectable, whereas there is a clear galanin expression. During postnatal life a small but increasing number of solitary post-mitotic VP neurons of the di/di rat undergoes a switch to a heterozygous phenotype. Here we report the presence of 7B2 and galanin in these heterozygous cells, which suggests that for the expression of 7B2, but not for that of galanin, the relative amount of mutant VP precursor must be diminished. Possible underlying mechanisms for this differential phenotypic expression of coexisting peptides are compartmentalization of precursor synthesis within the RER or a competition for sites involved in the translocation of the functionally reduced RER.
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PMID:Dynamics of 7B2 and galanin expression in solitary magnocellular hypothalamic vasopressin neurons of the homozygous Brattleboro rat. 138 Aug 70

A new protein, 7B2, has been found in the anterior, intermediate and posterior pituitary and the hypothalamus. It has been previously suggested that 7B2 is synthesized in the hypothalamus and is transported to the posterior lobe in a similar way to vasopressin (AVP). We examined the in vitro release of AVP and 7B2, using rat hypothalami in a perifused column system. Membrane depolarization with KCl (56 mM) caused a marked stimulation of AVP release (from 116% to 263% above basal values). Release of 7B2 was also stimulated by potassium from 106% to 212% above basal values. Potassium pulses in calcium-free medium failed to release AVP or 7B2. Osmotic and cholinergic stimulation increased AVP secretion by 205% and 282% above basal values, respectively, but had no significant effect on 7B2 secretion. Chromatographic profiles of perifusion media revealed one immunoreactive 7B2 peak eluting at a coefficient of 0.34 corresponding to that of rat hypothalamic 7B2. Similarly AVP coeluted with AVP standard. Thus AVP and 7B2 are differentially released by cholinergic and osmotic stimuli in vitro.
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PMID:Comparative studies on the release of vasopressin and 7B2 from isolated hypothalami. 221 1

Analysis of peptides purified from high and low molecular weight fractions of rabbit atrial extracts indicates that the sequence of the first 30 residues of rabbit atriopeptigen exhibits 80% homology with the rat peptide, and that the low molecular weight rabbit peptide (28 residues) is identical to rat atriopeptin 28 (AP 28). The effects of infused 1-deaminoarginine8-vasopressin (dAVP) and phenylephrine, volume expansion, and water immersion on AP release into the circulation of the rabbit was studied. Neither dAVP, nor water immersion elevated right atrial pressure (RAP) or plasma AP levels in the anesthetized rabbits. Phenylephrine induced a sustained increase in systemic blood pressure and right atrial pressure which was accompanied by elevated plasma AP immunoreactivity which appeared to be identical to rat AP-28 on HPLC. There is obviously a preferential conservation of the AP sequence, since the C-terminal peptide is exactly the same in rabbit, rat and mouse and differs from human, dog, cow and pig only by the single substitution of an isoleucine for a methionine residue.
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PMID:Identification of the cardiac and circulating form of atriopeptin in rabbit. 294 16

Immunoreactivity to the secretory protein 7B2 (IR-7B2) colocalizes with both AVP and Om in separate groups of neurons in the supraoptic nucleus. In mutant Brattleboro rats, which have aberrant AVP, which results in diabetes insipidus, 7B2 appears to be markedly decreased in vasopressinergic neurons and absent in their corresponding neurohypophyseal terminals. In contrast, no dramatic differences could be observed in oxytonergic somatas and fibers.
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PMID:[Decrease in the immunoreactivity of protein 7B2 in vasopressinergic cells in the supraoptic nucleus and in fibers of the neurohypophysis, in Brattleboro rats]. 314 72

The unlabeled antibody (peroxidase-anti-peroxidase) method was used to simultaneously localize vasopressin and a novel pituitary protein designated '7B2' in rat hypothalamus and pituitary. Results showed the common localization of both substances within magnocellular neurons of supraoptic, supraoptic retrochiasmic and paraventricular nuclei. The distribution was also similar in the inner zone of the median eminence and in the posterior lobe of the pituitary gland. Only 7B2 antiserum labeled the external zone of the median eminence and the intermediate and anterior lobes of the pituitary. In the Brattleboro rat the anterior and intermediate lobes were strongly labeled with 7B2-IR and there was some 7B2-staining in the hypothalamus and the posterior lobe, but the intensity of the reaction was diminished.
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PMID:Immunoreactivity of vasopressin and a novel pituitary protein '7B2' in Long-Evans and Brattleboro rat hypothalamus and hypophysis. 390 56

The regional distribution of a novel pituitary protein (7B2) in the rat brain was studied using a specific and sensitive radioimmunoassay. Immunoreactive (IR)-7B2 was distributed throughout the brain, with the highest concentrations in the pituitary, hypothalamus and basal ganglia. Immunoreactive 7B2 from the brain and other tissues had an apparent molecular weight of around 20,000 as estimated by SDS-polyacrylamide gel electrophoresis as observed with other tissues. In homozygous Brattleboro rats which do not synthesize vasopressin or its associated neurophysin, IR-7B2 levels in the brain and pituitary gland were shown to be similar to those of control animals. Furthermore, the molecular weight of 7B2 in the brain and pituitary gland of homozygous Brattleboro rats was similar to that of control animals.
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PMID:Regional distribution of a novel pituitary protein (7B2) in the rat brain. 402 92

A novel precursor neuropeptide termed 7B2 is present within specific brain areas, including the hypothalamic magnocellular neurosecretory neurons, and appears to be processed to smaller fragments. In order to determine whether specific C-terminal fragments of 7B2 might exert local effects on neurosecretory cells, we used intracellular current-clamp recordings in supraoptic neurons maintained in superfused hypothalamic explants to evaluate membrane potential and resistance changes in 25 supraoptic nucleus neurons during bolus applications of 7B2 174-186 and two other C-terminal peptide fragments 7B2 156-173 and 7B2 141-150. In 15 supraoptic neurons, only the 7B2 174-186 fragment induced a gradual 2-8 mV membrane depolarization that lasted for 4 to 30 min and was accompanied by 15+/-8% reduction in input resistance. Immunocytochemical identification of the recorded cells revealed that both vasopressin (VP)- and oxytocin (OT)-containing neurons were depolarized by 7B2 174-186. These data suggest that 7B2 174-186 is a biologically active fragment of 7B2 and may regulate the excitability of magnocellular supraoptic nucleus neurons.
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PMID:Depolarizing action of secretory granule protein 7B2 on rat supraoptic neurosecretory neurons. 868 Apr 21

7B2 is a neuroendocrine chaperone interacting with the prohormone convertase PC2 in the regulated secretory pathway. Its gene is located near the Prader-Willi syndrome (PWS) region on chromosome 15. In a previous study we were able to show 7B2 immunoreactivity in the supraoptic nucleus (SON) or the paraventricular nucleus (PVN) in only three of five PWS patients. Here we report that in contrast with five other PWS patients, the neurons in the hypothalamic SON and PVN of the two 7B2-immunonegative PWS patients also failed to show any reaction using two antibodies directed against processed vasopressin (VP). On the other hand, even these two cases reacted normally with five antibodies that recognize different parts of the VP precursor. This finding pointed to a processing defect. Indeed, the same patients had no PC2 immunoreactivity in the SON or PVN, whereas PC1 immunoreactivity was only slightly diminished. In conclusion, in the VP neurons of two PWS patients, greatly reduced amounts of 7B2 and PC2 are present, resulting in diminished VP precursor processing.
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PMID:Attenuation of the polypeptide 7B2, prohormone convertase PC2, and vasopressin in the hypothalamus of some Prader-Willi patients: indications for a processing defect. 946 79

The homozygous Brattleboro rat (di/di) synthesizes a vasopressin (VP) precursor with an aberrant C-terminus, which causes a hypothalamic form of diabetes insipidus. The neuroendocrine polypeptide 7B2 is present in VP and oxytocin (OT) neurons of the supraoptic and paraventricular nucleus of the hypothalamus in wild type rats. However, in the di/di rat 7B2 immunoreactivity is absent in the VP cell population, whereas 7B2 levels within the OT cells are unaffected. Remarkably, there is no obvious difference in 7B2 transcript levels between VP and OT neurons in the di/di rat hypothalamus. This study shows that the presence of mRNA does not automatically result in the subsequent synthesis of its protein. Cellular mechanisms underlying this discrepancy are discussed.
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PMID:Lack of translation of normal 7B2 mRNA levels in hypothalamic mutant vasopressin cells of the homozygous Brattleboro rat. 954 70


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