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)

Dissociation of ionizing groups in leghemoglobin from Lupinus Luteus in the wide pH range was studied by potentiometric titration. 16 + 8 groups were shown to the titrated at acid pH. One part of them are normally titrating groups and the other one is associated with some details of protein structure. At neutral pH 4 groups are titrated, the titration of 3 of the show histeresis. Five lysins are normally titrated at the alkaline pH. among them one is possibly responsible for an alkaline dissociation. 13 charged groups take part in the dissociation, 3-4 are titrated inreversibly. The experimental results are analyzed in terms of Linderstrom-Lang-Tanford representation and are discussed on the basis of primary and three-dimentional leghemoglobin structure.
Mol Biol (Mosk)
PMID:[Acid-base equilibrium of yellow lupine ferrileghemoglobin. potentiometric studies]. 2 78

1. Complexes of human trypsin and human granulocyte elastase with alpha1-anti-trypsin and alpha2-macroglobulin were isolated and injected intravenously into human volunteers. 2. The elimination of alpha2-macroglobulin complexes with trypsin and elastase followed single-exponential functions with half-lives of 9 and 12 min respectively. The complexes showed no tendency to dissociate. 3. Complexes of alpha1-anti-trypsin with trypsin persisted in the circulation much longer, with a half-life of 3-5 h; complexes of alpha1-anti-trypsin with elastase had an intermediate half-life of 1 h. 4. Dissociation was observed of alpha1-anti-trypsin complexes with transfer of trypsin and elastase to alpha2-macroglobulin. 5. Dialysable radioactivity appeared in the urine soon after the injection of alpha2-macroglobulin complexes, which suggested a breakdown of complexes by cells in the reticuloendothelial system. Radioactivity over the liver achieved maximum values within 30-40 min after the injection of alpha2-macroglobulin complexes but not until 50-70 min after the injection of alpha1-anti-trypsin comlexes. 6. These results support the concept of a key position for alpha2-macroglobulin in the protective mechanisms against endogenous proteases.
Clin Sci Mol Med 1976 Jul
PMID:The disappearance of enzyme-inhibitor complexes from the circulation of man. 5 54

The cytoplasmic recptor (CR) in rat epididymal 105,000 g supernatant was separated from the androgen-binding protein (ABP) by gel electrophoresis following labeling with [1,2,6,7-3H]-testosterone in vivo. ABP disappeared from epididymal supernatants after castration of hypophysectomy, while CR remained unchanged. CR was evenly distributed between caput and cauda, while much more ABP was present in caput. Properties of CR in epididymis and prostate were similar and distinctly different from ABP. Binding to CR was destroyed by charcoal treatment (1 mg/mg protein) of supernatant for 0 degrees C for 6 h, heating at 50 degrees C for 30 min, or exposure to the sulfhydryl blocking reagent, p-chloromercuriphenylsulfonate (1mM) at 25 degrees C for 30 min, while binding to ABP was unaffected. The isoelectric pH of CR (5.8) was higher than that of ABP (4.6). Dissociation of radioactive 5alpha-dihydrotestosterone (DHT) from CR and nuclear receptors was extremely slow (half-time at 0 degrees C is greater than 2 days), while dissociation from ABP was rapid (half-time at 0 degrees C is similar to 6 min). Cyproterone acetate (250 mg/100 g body weight) inhibited binding to CR both in epididymis and ventral prostate but did not affect binding to ABP. Nuclear uptake was inhibited by cyproterone to the same extent as binding to CR, indicating that nuclear uptake and binding are dependent on CR and independent of ABP. The time-course of uptake and binding in epididymal supernatant and nuclear fractions was essentially the same 1 day after bilateral castration when both CR and ABP were present or 8 days after castration when CR alone was present. It is concluded that the cytoplasmic receptor for androgen in rat epididymis has properties very similar to the androgen receptor in ventral prostate but different from ABP.
Mol Cell Endocrinol 1975 Aug
PMID:Androgen-binding proteins in rat epididymis: properties of a cytoplasmic receptor for androgen similar to the androgen receptor in ventral prostate and different from androgen-binding protein (ABP). 17 Jan 53

The synthesis of the four enzymes of the deo operon in Escherichia coli is known from in vivo experiments to be subject to a double negative control, exerted by the products of the cytR and deoR genes. A DNA-directed in vitro protein synthesizing system makes the deo enzymes (exemplified by thymidine phosphorylase) in agreement with in vivo results. Enzyme synthesis is stimulated by cyclic AMP and repressed by the cytR and deoR gene products. Repression by the cytR repressor is reversed by cytidine or adenosine in the presence of cyclic AMP, while repression by the deoR repressor is reversed by deoxyribose-5-phosphate. Assays for the presence of the cytR and deoR repressors were established by use of S-30 extracts prepared from the regulatory mutants. Dissociation constants for repressor-operator binding as well as for repressor-inducer interactions have been estimated from the results.
Mol Gen Genet 1978 Feb 16
PMID:Regulation of the deo operon in Escherichia coli: the double negative control of the deo operon by the cytR and deoR repressors in a DNA directed in vitro system. 20 61

The miniR1-(Rsc)-plasmids which derive from the copy mutant R1drd-19B2 (pKN102) are non-conjugative extrachromosomal elements which can not be co-transferred by various transfer factors to recipient strains under standard mating conditions. The attempts to mobilize Rsc11 by F'lac lead to transconjugants carrying F'lac::Tn3 with Tn3 mainly inserted into the lac operon. In addition it can be shown that Rsc11 can become inserted as a complete unit into the transfer factor giving rise to rather unstable recombinant intermediates. Dissociation of these intermediates may lead to alterations of the original plasmids. The Tn3 part of Rsc13 can be enlarged or deleted by in vitro manipulations. In vitro insertion of EcoRI-fragments into an EcoRI+ site of Tn3 leads to new transposable units which can be transposed to the RTF part of R1. This new genetic entity can be stably integrated into the chromosome of E. coli by integrative suppression of a dnaAts-mutation. Deletions at one end or the central region of Tn3 abolish the capability of transposition. However, the Rsc-plasmids containing the deleted Tn3 can still be inserted into the transfer factor as complete units. The resulting recombinants are unstable leading after dissociation in some cases to new plasmids with altered properties.
Mol Gen Genet 1977 Nov 29
PMID:Transposition and insertion of intact, deleted and enlarged ampicillin transposon Tn3 from mini-R1 (Rsc) plasmids into transfer factors. 34 Sep 18

Electrophoretic mobility, amino acid composition and salt dissociation of histones isolated from sperm of sea urchin Strongylocentrotus intermedius and calf thymus cells were studied. The special arginine-rich histone fraction (I) has been observed in sea urchin sperm chromatin, this fraction being absent in calf thymus chromatin. Dissociation of lysine-containing histone fractions from sea urchin chromatin occured in the range of 0.7 to 1.0 M NaCl concentrations. H1 of calf thymus chromatin was totally extracted with 0.6 M NaCl. In the course of a further increase of salt concentrations (up to 1.5 M NaCl) a practically total extraction of histones from sperm chromatin was observed, while about 20% of proteins remained bound to DNA in thymus chromatin after extraction with 2.0 M NaCl. The template activity of non-extracted DNP preparations from urchin sperm was equal to 2-3% of that of totally deproteinized DNA. The template activity of DNP gradually increased at protein extraction from DNP preparations. The hybridization capacity of RNA transcribed on partially dehistonized DNP templates in vitro also increased.
Mol Biol (Mosk)
PMID:[Sea urchin sperm DNP. I. Chemical composition and template properties of DNP]. 56 76

1. The total number of specific dexamethasone-binding sites in rat heart and liver cytosol was measured at intervals after adrenalectomy. 2. Between 12 and 48 h after adrenalectomy there was a significant increase in the number of binding sites in both heart and liver cytosol. Affinity was unchanged. 3. Of the [3H]corticosterone bound to liver cytosol proteins after an intravenous injection 98% disappeared within 2 h in vivo. Dissociation of endogenous corticosterone-receptor complexes in liver cytol will thus be substantially complete some hours before the number of receptors increases. 4. It was concluded that there is a true increase in the number of glucocorticoid receptors occurring principally between 12 and 48 h after suppression of endogenous steroids.
Clin Sci Mol Med 1976 Nov
PMID:Changes in cardiac and hepatic glucocorticoid receptors after adrenalectomy. 99 46

The subunit dissociation of human hemoglobin A by the aliphatic acid salts at neutral pH has been investigated by light-scattering molecular-weight measurements at 630 nm. Dissociation of hemoglobin tetramers to alphabeta dimers is observed in essentially all experiments at low to intermediate levels of salt concentrations, below the denaturation transitions, described in the accompanying paper (Ibanez, V.S., and Herskovits, T.T. (1976), Biochemistry 15, preceding paper in this issue). The effectiveness of the salts as subunit dissociating agent, reflected by the slopes, s, of the plots of deltaGDdegrees, the standard free energy of dissociation, vs. [D], the salt concentration, is found to increase with increasing alkyl chain length or hydrocarbon content of the salt. Estimates of the apparent number of amino acid sites at the areas of contact per alphabeta dimer formed, N', based on the slopes of the higher members of the series have been obtained using the equation, deltaGDdegrees = deltaGD,Wdegrees - 2N'RTKB[D]. Independent estimates of the binding constant, KB, required for these calculations were based on free-energy transfer data of hydrophobic amino acid alkyl groups and protein denaturation data. Our estimates of N' denaturation data. Our estimates of N' obtained with the more reliable data of the higher members of salt series are in the ranges of 19 and 27 amino acid groups, shown by the x-ray crystallographic structure of horse and human hemoglobin of Perutz (Perutz, M.F., et al. (1968), Nature (London) 219, 131) and Fermi ((1975) J. Mol. Biol. 97, 237) for the smaller alpha1 beta2 contact areas in the tetrameric structure. The lower estimates than 27 based on our dissociation of human hemoglobin suggest that several of the amino acid residues in the contact areas of the subunits are partially exposed to solvent. The increasing effectiveness of the higher mn imporant source of stabilization of the tetrameric structure of hemoglobin.
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PMID:Light-scattering investigations of the subunit dissociation of human hemoglobin A. Effects of the aliphatic acid salts. 100 84

Previous current-clamp work has shown that dihydropyrazole insecticides block sodium channels in tonic sensory receptors and in axons depolarized by high K+ external solutions and that hyperpolarization removes the block [Pestic. Sci. 28:389-411 (1990)]. Voltage-clamp studies on internally perfused crayfish giant axons were done to confirm and extend these observations. At -100 mV dihydropyrazoles had little effect on the sodium current, but at more depolarized potentials they blocked it from either face of the membrane. The onset of block following a holding potential change or during wash-in of a dihydropyrazole was very slow, with a time constant of several minutes, and, although block could be removed with a similar time course by hyperpolarization, the effects of the insecticides could not be reversed by prolonged washing. Dihydropyrazoles did not affect delayed rectifier potassium currents in the axon. The voltage-dependent block could be described as a uniform shift of the steady state (slow) sodium inactivation (S infinity) curve in the direction of hyperpolarization, indicative of selective binding to inactivated states of the channel. Using hyperpolarizing prepulses to remove slow inactivation, block of sodium channels by dihydropyrazoles could be measured directly at holding potentials as positive as -50 mV, and it could be demonstrated that block saturated near -70 mV, consistent with a dependence on slow inactivation. The data were fit to a model tha assumes the dihydropyrazole binds to the slow-inactivated state of the channel on a one to one basis. Dissociation constants obtained from this analysis were similar to those obtained from analysis of inhibition of the binding of [benzoyl-2,5-3H]-batrachotoxinin A 20-alpha-benzoate by the same dihydropyrazoles. In axons whose fast or slow inactivation gates had been removed by N-bromoacetamide or trypsin, respectively, dihydropyrazoles still blocked sodium current, indicating that dihydropyrazoles can block the channel as well as enhance the normal slow inactivation process.
Mol Pharmacol 1992 Jan
PMID:Slow voltage-dependent block of sodium channels in crayfish nerve by dihydropyrazole insecticides. 131 Jan 38

Sequences sharing homology to the transposable element Activator (Ac) are prevalent in the maize genome. A cryptic Ac-like DNA, cAc-11, was isolated from the maize inbred line 4Co63 and sequenced. Cryptic Ac-11 has over 90% homology to known Ac sequences and contains an 11 bp inverted terminal repeat flanked by an 8 bp target site duplication, which are characteristics of Ac and Dissociation (Ds) transposable elements. Unlike the active Ac element, which encodes a transposase, the corresponding sequence in cAc-11 has no significant open reading frame. A 44 bp tandem repeat was found at one end of cAc-11, which might be a result of aberrant transposition. The sequence data suggest that cAc-11 may represent a remnant of an Ac or a Ds element. Sequences homologous to cAc-11 can be detected in many maize inbred lines. In contrast to canonical Ac elements, cAc-11 DNA in the maize genome is hypermethylated and does not transpose even in the presence of an active Ac element.
Mol Gen Genet 1992 Jun
PMID:A maize cryptic Ac-homologous sequence derived from an Activator transposable element does not transpose. 132 Jan 87


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