Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Data on the kinetics of 1H greater than 3H exchange between water and C(8)H groups of guanylic residues in the poly(rG) and poly poly(rG)-poly(rC) are presented. Furthermore, optical properties (CD spectra and hyperchromism) of neutral solutions of these polymers from 20 to 100 degrees C are described. It is shown that the exchange in poly(rG) within the temperature range from 20 to 80 degrees C proceeds faster than in rGMP. Within the temperature range from 20 to 40 degrees C such an acceleration of the exchange is observed also in poly(rG)-poly(rC). According to the ylide mechanism of the exchange reaction the observed accleration of the exchanged in in C(8)H groups of guanylic residues is considered as a consequence of an increase of the positive charge at N(7) atoms. This effect is due to formation of additional hydrogen bonds in which N(7) atoms take part. The exchange in poly(rG)-poly(rG) at temperatures hihger than 75 degrees C, when these additional hydrogen bonds are absent, proceeds more slowly than in rGMP. Such picture is usual in other previously studied polynucleotides whose structure in solution is stabilized only by Watson - Crick hydrogen bonds and stacking interactions. The data obtained support a Guschelbauer's model of the four-stranded stranded poly(rG). They also indicate the posibility of associates formation in poly(rG)-poly(rC) solutions at temperature lower than 40 degrees C being stabilized by hydrogen bonds in which N(7) atoms of guanylic residues take part.
Mol Biol (Mosk)
PMID:[Reaction capabilities and structure of poly(rG) and poly(rG)-poly(rC) in solution by the method of the kinetics of hydrogen ion exchange]. 18 2

1. The bronchial response to alpha-adrenoreceptor stimulation has been investigated in normal and asthmatic subjects with a specific alpha-receptor agonist, methoxamine hydrochloride, after atropine and beta-adrenergic blockade. 2. No significant changes in forced expiratory volume in 1 s (FEV1.0) were seen in normal subjects. 3. Methoxamine inhalation caused mild symptomatic wheezing and significant falls in FEV1.0 in asthmatic subjects. No change in FEV1.0 occurred after inhalation of distilled water as control. 4. It therefore appears that methoxamine causes bronchoconstriction in asthmatic subjects through its alpha-adrenergic-stimulating properties, since we were not able to detect any beta-receptor-blocking activity of methoxamine on the airways.
Clin Sci Mol Med 1978 Mar
PMID:The effect of alpha-adrenoreceptor stimulation on the airways of normal and asthmatic man. 20 43

Polarity of double and ternary water-nonelectrolyte systems at the component ratio, corresponding to a half-transition point of DNA from B to A form was evaluated from ESR spectra of a spin-probe. In all cases examined the isotropic super-fine splitting constant (aN) is the same with an accuracy of 0.05 gauss. Small differences in aN are well correlated with the concentration of the groups which are able to form hydrogen bonds with the nitroxide fragment of the radical. Thus, media polarity is a factor which determines the A--B equilibrium of DNA in solution.
Mol Biol (Mosk)
PMID:[Polarity of the environment as a factor determining DNA conformation]. 20 79

1. The effects of adrenalectomy on the adenylate cyclase--adenosine 3':5'-cyclic monophosphate (cyclic AMP) system of rat renal medulla were examined to evaluate the mechanism of the impaired water diuresis in glucocorticoid deficiency. 2. Concentrations of cyclic AMP in medullary tubules from adrenalectomized rats were significantly higher than in the tubules from control animals both in the presence and absence of antidiuretic hormone. 3. This abnormality was corrected by the treatment in vivo of the adrenalectomized rats with dexamethasone, but addition of this drug to the incubation medium did not abolish the differences in cyclic AMP between tubules from adrenalectomized and normal rats. 4. The activity of adenylate cyclase or cyclic AMP phosphodiesterase in vitro was not affected by adrenalectomy. 5. In glucocorticoid deficiency, the concentration of cyclic AMP in medullary tubules is increased both with and without antidiuretic hormone. This abnormality may render medullary tubules more permeable to water and may underlie the impaired water diuresis in glucocorticoid deficiency.
Clin Sci Mol Med 1978 May
PMID:Effects of glucocorticoid deficiency on renal medullary cyclic adenosine monophosphate of rats. 21 86

The possibility of using gamma resonance spectroscopy (GRS) for studying the dynamics of water-protein systems is shown in the present work. The experiments were carried out on an albumin-water system. The results obtained are compared with those obtained by the spin label method under the same conditions. The different behaviour of Fe ions which are firmly- and weakly-related with the protein matrix allows to separate the mobility of the whole protein macromolecule and also the mobility of its subunits.
Mol Biol (Mosk)
PMID:[Study of the dynamics of water-protein systems by the technic of gamma-resonance spectroscopy]. 22 May 24

The rate of water proton relaxation of the solutions of human serum albumin (HSA) modified by different spin labels has been investigated by spin echo technique. The rate of proton relaxation in the presence of the labeled HSA is higher than that in water solutions of spin labels. The proton relaxation data of the protein solutions can be explained by local properties of the water, bound with the protein (in the regions of spin labels) which seem to resemble those of water-glycerol solutions. The rate of proton relaxation was decreased in the presence of steroids that can be explained by a decrease of the local microviscosity of the water-protein matrix due to interaction of steroids with HSA.
Mol Biol (Mosk)
PMID:[Interaction of steroids with human serum albumin by spin echo technique and paramagnetic sound methods]. 22 29

The binding of ethidium bromide and acriflavin dyes with DNA modified with a spin-labelled analogue of ethylene imine has been studied. These spin-labels were shown to bind covalently to DNA, at the same time the number of the dye molecules bound is decreased without any changes in the binding constant. Analysis of ESR spectra of the samples in the frozen 50% water-glycerol solution at 77 degrees K for spin-labelled DNA has shown that addition of the dyes increases distance between the labels. This fact might be explained by an increase in DNA length upon formation of the complex with dye molecules.
Mol Biol (Mosk)
PMID:[Study of DNA-dye interaction by spin-labels]. 22 30

Various water-insoluble cannabinoids as well as SP-111A, the water-soluble derivative of delta 9-tetrahydrocannabinol (delta 9-THC), reduced hCG and dibutyryl-cAMP stimulated testosterone production by rat testicular Leydig cell preparations. With 0.15 microM (0.05 micrograms/ml) 8-beta-OH-delta 9-THC the inhibition was about 50% of stimulated testosterone synthesis. Dose-related inhibitions were apparent with other cannabinoids and their order of potency in inhibiting stimulated steroidogenesis by the interstitial cells in vitro was found to be: 8-beta-OH-delta 9-THC greater than or equal to 11-OH-delta 9-THC greater than CBN = CBD = CBG greater than or equal delta 9-THC = delta 8-THC. The non-stimulated, basal, steroidogenesis was not affected even with 15 microM cannabinoids. The incorporation of L-[U-14C]leucine into the protein of Leydig cells was markedly reduced by 15 microM cannabinoids under both basal and stimulated conditions. The inhibition of steroidogenesis as well as protein synthesis in rat testicular Leydig cell preparations by various cannabinoids cannot be correlated with their psychoactivity. The present data suggest that cannabinoids at very low concentrations may interfere directly in Leydig cells with both protein and testosterone synthesis, and thus with their function.
Mol Cell Endocrinol 1979 Jul
PMID:Effects of cannabinoids on testosterone and protein synthesis in rat testis Leydig cells in vitro. 22 40

Alkaline earth and alkali metal superoxides and peroxides, gamma-Fe2O3 and carbon suboxide polymer are proposed to be constituents of the Martian surface material. These reactive substances explain the water modified reactions and thermal behaviors of the Martian samples demonstrated by all of the Viking Biology Experiments. It is also proposed that the syntheses of these substances result mainly from electrical discharges between wind-mobilized particles at Martian pressures; plasmas are initiated and maintained by these discharges. Active species in the plasma either combine to form or react with inorganic surfaces to create the reactive constitutents.
J Mol Evol 1979 Dec
PMID:A model of Martian surface chemistry. 23 Mar 58

The oxidation-reduction equilibrium of the gamma chains of human fetal hemoglobin (Hb F) has been studied and compared with that of the alpha and beta chains of human adult hemoglobin (Hb A). The effects of the sulfhydryl (--SH) reagents, iodoacetate, iodoacetamide, and p-mercuribenzoate (PMB), on the three kinds of chains and on Hb F have been compared. The midpoint potentials (E-m) of all three sorts of chains are lower than those of tetrameric hemoglobin A or F. The E-m values of alpha chains are the lowest, E-m = 0.049 volt at 6 degrees, and are unaffected by pH change or by PMB treatment, at least from pH 6 to 8. The E-m values of beta-SH chains are higher; E-m = 0.102 volt at pH 7, decreasing to 0.050 volt at pH 8, both at 6 degrees. These results agree with those of Banerjee and Cassoly ((1969) J. Mol. Biol. 42, 337-349). They reported no effect of PMB on beta chains, but we find that 2 eq of PMB/chain raise E--M to 0.139 volt at pH 7 at 6 degrees, chiefly as the result of reaction at beta-93, not at beta-112. Carboxymethylation at beta-93 has an insignificant effect compared with that of PMB. The oxidation-reduction potential of gamma chains is similar to that of beta chains. E-m = 0.098 volt at pH 7 at 6 degrees, decreasing to 0.064 at pH 8 and 0.010 at pH 9. The effects of --SH reagents, reacting at position gamma-93 (the only --SH group present in gamma chains), are essentially the same as those seen with beta chains. The oxidation-reduction potential of Hb F is almost identical with that of Hb A, except for being 0.008 volt lower at pH 6 at 6 degrees. This agrees with the results reported by Flohe and Uehleke ((1966) Life Sci. 5, 1041-1045). PMB or iodoacetamide treatment lowers E-m by 0.02 to 0.03 volt, depending on the pH, from 6 to 9, in much the same way as previously reported for Hb A(Brunori, M., Taylor, J.F., Antonini, E., Wyman, J., and Rossi-Fanelli, A. (1967) J. Biol. Chem. 242, 2295-2300). The "residual oxidation Bohr effect" noted in Hb F can be attributed to the oxidation Bohr effect of the gamma chains. The apparent pK of the heme-linked water molecule was found at 25 degrees to be, for Hb F, 8.1; for gamma-SH chains, 7.85; for gamma-PMB chains, 8.35; and for gamma chains treated with iodoacetate, 7.80. Sedimentation coefficients, s-20, w, at a protein concentration of 5 mg/ml, were found to be, for fetal hemoglobin 4.09, for iodoacetamide-treated fetal hemoglobin 4.04, for PMB-treated fetal hemoglobin 3.41, for fetal gamma-SH chains 4.25, and for fetal gamma-PMB chains 3.08.
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PMID:Oxidation-reduction potentials of human fetal hemoglobin and gamma chains. Effects of blocking sulfhydryl groups. 23 6


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