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)

1. Whole-body intracellular pH (pHi) was measured by the 14C-labelled DMO method in twenty-four control subjects, eighteen normal subjects with induced acute metabolic alkalosis, ten normal subjects with induced acute metabolic acidosis, twelve normal subjects with chronic acidosis and in fifteen patients with chronic renal insufficiency and acidosis. 2. The change in pHi per unit change in extracellular pH is significantly larger in acute metabolic alkalosis than in acute metabolic acidosis. In chronic metabolic acidosis, pHi decreased in proportion to the total amount of ammonium chloride administered; pHi was normal in patients with uraemic acidosis. 3. These observations confirm the role that tissue buffers play in the protection of the cellular environment in some forms of acidosis. When the acid load overwhelms tissue buffer capacity, pHi becomes a function of extracellular pH. 4. Cells seem more protected from acute acidosis than from acute alkalosis.
Clin Sci Mol Med 1977 Feb
PMID:Effects of metabolic alkalosis, metabolic acidosis and uraemia on whole-body intracellular pH in man. 1 3

cAMP independent glycogen synthase kinase and phosvitin kinase activity was purified from the 180 000 x g supernatant of human polymorphonuclear leukocytes by ammonium sulphate precipitation and phosphocellulose chromatography. The cAMP independent glycogen synthase kinase eluted from the phosphocellulose at 0.54 M NaCl (peak A) separate from the major phosvitin kinase eluting at 0.68 M NaCl (peak B). The kinase activity of both peaks tended to form aggregates, but in the presence of 0.6 M NaCl, the peak B enzyme had Mr 250 000, 7.2S and the peak A enzyme Mr 38 000, 3.8S. The ratio between synthase kinase and phosvitin kinase activity in peak A was 1:3.2 and in peak B 1:31.4. In addition the kinase activities differed with respect to sensitivity to temperature, ionic strength and CaCl2. It is suggested that the peak A enzyme represents the cAMP independent glycogen synthase kinase of leukocytes, whereas the peak B enzyme is a phosvitin kinase, which is insignificantly contaminated with some synthase kinase (peak A) and contains a separate, second synthase kinase. Synthase kinase had Kmapp 4.2 microM for muscle glycogen synthease I and Kmapp 45 microM for ATP. GTP was a poor substrate. The activity was not influenced by cyclic nucleotides, Ca2+, or glucose-6-P. Synthase I from muscle and leukocytes was phosphorylated to a ratio of independence of less than 0.05.
Mol Cell Biochem 1979 Jul 15
PMID:Purification and properties of cAMP independent glycogen synthase kinase and phosvitin kinase from human leukocytes. 4 Jan 8

Two distinct steroid-binding proteins are present in rabbit plasma. One of the proteins (TeBG) binds [3-H]5 alpha-dihydrotestosterone (5 alpha DHT) and [3-H]testosterone. The affinity of this binding protein for 5 alpha DHT was 3-4 times greater than for testosterone. Binding of [3-H]5 alphaDHT could be inhibited by unlabeled 5 alpha DHT, testosterone, 5 alpha-androstan-3 alpha,17 beta-diol (3 alpha-diol), and 17 alpha-methyl- B-testosterone (skf) 7690). The relative affinity of the competitors was: 5 alpha DHT greater than 3 alpha-diol greater than testosterone greater than SKF 7690. The antiandrogens, cyproterone (1,2 alpha-methylene-6-chloro-pregn-4,6-diene-17 alpla-ol-3,20 dione), cyproterone-17-acetate, and 6 alpha-bromo-17 beta-hydroxy-17 alpha-methyl-4-oxa-5 alpha-androstan-3-ine (BOMT) were ineffective in competing for [3-H5d alpha DHT binding sites, as were 4-androstene-3, 17-dione, 17 beta-estradiol (E2), progesterone, and cortisol. The formation of the [3-H]5 alpha DHT-TeBG complex was extremely rapid; the binding reaction was essentially completed in 15 s. The complex dissociated rapidly in the presence of charcoal. The dissociation rate constant (Kdiss) was 0.157 min- minus 1 and the dissociation half-time t-1/2) was 4.5 min. In the presence of charcoal and unlabeled 5 alpha DHT the Kdiss was 0.268 min- minus 1 and the t=1/2 was 2.6 min. The sedimentation coefficient of TeBG was congruent to 4.6 S and its molecular weight, estimated by gel filtration on a calibrated Sephadex G-200 column, was congruent to 75,000. The concentration of TeBG in male rabbit plasma decreased with sexual maturation and was approximately three times higher in adult females than in adult males. The other protein (CBG) bound both [3-H]cortisol and [3-H]progesterone. Binding of these compounds could be inhibited by unlabeled cortisol and progesterone, but not by unlabeled 5 alpha DHT, testosterone, or E2. CBG had a sedimentation of congruent to 3.9 S and an apparent molecular weight of congruent to 105,000. TeBG could be separated from CBG by a 60% ammonium sulfate precipitation and by gel filtration chromatography. Both proteins are thermolabile; TeBG is inactivated at temperatures above 30 degrees C and CBG is inactivated at temperatures above 50 degrees C.
Mol Cell Endocrinol 1975 May
PMID:Steroid-binding proteins in rabbit plasma: Separation of testosterone-binding globulin (TeBG) from corticosteroid-binding globulin (CBG), preliminary characterization of TeBG, and changes in TeBG concentration during sexual maturation. 4 21

Testosterone-estradiol binding globulin (TeBG) is known to change in various endocrinological environments such as estrogen administration, pregnancy and aging. Several methods, including dextran coated charcoal, equilibrium dialysis and ammonium sulfate precipitation, were used to measure the binding capacity of TeBG, but these were not simple and accurate. We therefore measured TeBG levels in human serum by means of a steady state polyacrylamide gel electrophoresis and found that this method was simple and accurate for the determination of the binding capacity of TeBG. The value of TeBG in normal adults (27 approximately 32 years old) was 3.88 +/- 0.45 x 10(-8) Mol and in patients with benign prostatic hypertrophy the value was high (5.49 +/- 1.35 x 10(-8) Mol compared to that of normal adults.
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PMID:[A steady state polyacrylamide gel electrophoresis for the determination of testosterone-estradiol binding globulin (author's transl)]. 8 59

One allele at each of the five nit loci in Neurospora crassa together with the wild type strain have been compared on various nitrogen sources with regard to (i) their growth characteristics (ii) the level of nitrate reductase and its associated activities (reduced benzyl viologen nitrate reductase and cytochrome c reductase) (iii) the level of nitrate reductase and (iv) their ability to take up nitrite from the surrounding medium. Results are consistent with the hypothesis that nit-3 is the structural gene for nitrate reductase, nit-1 specifies in part of molybdenum containing moiety which is responsible for the nit-3 gene product dimerising to form nitrate reductase, nit-4 and nit-5 are regulator genes whose products are involved in the induction of both nitrate reductase and nitrite reductase and nit-2 codes for a generalised ammonium activated repressor protein. Studies on the induction of nitrate reductase (and its associated activities) and nitrite reductase in wild type, nit-1 and nit-3 in the presence of either nitrate or nitrite suggest that each enzyme may be regulated independently of the other and that nitrite could be true co-inducer of the assimilatory pathway. Nitrite uptake experiments with nit-2, nit-4 and nit-5 strains show that whereas nit-4 and nit-5 are freely permeable to this molecule, it is unable to enter the nit-2 mycelium.
Mol Gen Genet 1976 May 07
PMID:Biochemical studies on the nit mutants of Neurospora crassa. 13 3

Neurospora crassa can utilize various purine bases such as xanthine or uric acid and their catabolic products as a nitrogen source. The early purine catabolic enzymes in this organism are regulated by induction and by ammonium repression. Studies were undertaken to investigate purine base transport and its regulation in Neurospora. The results of competition experiments with uric acid and xanthine transport strongly suggest that uric acid and xanthine share a common transport system. It was also shown that the common transport system for uric acid and xanthine is distinct from a second transport system shared by hypoxanthine, adenine and guanine, and apparently also distinct from the transport system(s) for adenosine, cytosine and uracil. Regulation of the uric acid-xanthine transport system and the hypoxanthine-adenine-guanine transport system was studied. The results reveal that the uric acid-xanthine transport system is regulated by ammonium repression, but does not require uric acid induction. Neither ammonium repression nor uric acid induction controls the hypoxanthine-adenine-guanine transport system. A gene, designated amr, which is believed to be a positive regulatory gene for nitrogen metabolism of Neurospora crassa, was found to dramatically affect both the uric acid-xanthine transport system and the hypoxanthine-adenine-guanine transport system. A model for the action of the amr locus as a positive regulatory gene and for the interaction between the amr gene product and its recognition sites will be discussed.
Mol Gen Genet 1976 Dec 22
PMID:Genetic and metabolic regulation of purine base transport in Neurospora crassa. 13 63

A mutation leading to partial loss of NAD-linked ("catabolic') glutamate dehydrogenase does not affect the regulation of ammonium-repressible activities in Aspergillus nidulans. This mutation has been used to show that NAD-linked glutamate dehydrogenase does not normally participate in ammonium assimilation. A mutation leading to loss of NADP-linked ("anabolic') glutamate dehydrogenase has been used to show that NADP-linked glutamate dehydrogenase is not normally involved in glutamate catabolism. Strains defective in either enzyme are useful for determining which amino acids are metabolised via transamination to yield glutamate rather than via deamination to yield ammonium.
Mol Gen Genet 1975
PMID:A mutant of Aspergillus nidulans defective in NAD-linked glutamate dehydrogenase. 17 77

Bio-Gel A-5m chromatography has been used to separate apparent multiple forms of cyclic nucleotide phosphodiesterase from rat erythrocytes. Cyclic AMP phosphodiesterase was resolved by gel filtration into three peaks of activity with apparent molecular weights of about 300,000, 225,000 and 100,000, while cyclic GMP phosphodiesterase activity in gel column fractions was too low to permit meaningful estimates of its molecular weight. All three of the separated peaks of cyclic AMP phosphodiesterase activity displayed anomalous kinetic behaviour suggestive of negative cooperativity. The possibility that multiple phosphodiesterase activities could arise from in vitro alterations of a single enzyme was investigated. Similar changes in gel filtration profiles resulted when erythrocyte extracts were treated with trypsin or ammonium sulfate or were incubated at 37 degrees C. After these treatments, a large proportion of the enzyme activity occurred in low (ca. 100,000) molecular weight regions. The low molecular weight phosphodiesterase activities from untreated, incubated, and trypsin-treated extracts possessed similar properties. All were inhibited by methylxanthines, had pH optima of approximately 8.0, and similar kinetic properties and requirements for divalent cations. These observations raise the possibility that preparative procedures or limited proteolysis occurring during preparation and handling of extracts can contribute to the apparent multiplicity of enzyme forms seen after gel filtration of phosphodiesterase from rat erythrocytes and perhaps other cell types.
Mol Cell Endocrinol
PMID:Apparent multiple forms of cyclic AMP phosphodiesterase from rat erythrocytes. 18 74

As glutamine-dependent carbamoyl phasphate synthetase (CPS) activity in some organisms is composed of a glutaminase and an ammonium-dependent CPS, CPS- mutants in Neurospora crassa were examined for glutamine- and ammonium-dependent CPS activities. No evidence was found that the genetic location of these two functions were separable. This is discussed with reference to the close genetic proximity of the CPSpyr and aspartate carbamoyltransferase (ACT) structural gene (pyr-3) and the arg-2 gene which appears to specify a subunit responsible for glutamine utilisation in CPSarg.
Mol Gen Genet 1976 Dec 08
PMID:Glutamine utilization in both the arginine-specific and pyrimidine-specific carbamoyl phosphate synthase enzymes of eurospora crassa. 18 79

In Saccharomyces cerevisiae, argB and argC define two adjacent and complementing loci, with mutants defective in two consecutive steps of arginine biosynthesis: N-acetylglutamate kinase (AG-kinase) and N-acetylglutamyl-phosphate reductase (AGPreductase). These enzymic activities are readily separated by ammonium sulfate fractionation or Sephadex G-200 chromatography. This suggests that each activity is carried in vivo by a different protein. The synthesis of the two enzymes is coordinately regulated, with an 85-fold difference in specific activities between fully repressed and fully derepressed cells. Missence mutations of the argB locus are defective in AGkinase only. Nonsense mutations in the argB locus are defective in both activities. Missense and nonsense mutations in the argC locus are defective in AGPreductase, with a few alleles also showing a reduced level of AGkinase. These data are best explained by assuming that argB and argC are two genes transcribed as a single messenger from argB to argC. This messenger produces in vivo two distinct proteins corresponding to the argB and argC gene products, either because translation can be initiated at the beginning of both genes, or because a large polypeptide is specifically cut in vivo to yield the gene products of argB and argC.
Mol Gen Genet 1979 Jan 11
PMID:Organization and expression of a two-gene cluster in the arginine biosynthesis of Saccharomyces cerevisiae. 22 May 8


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