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. Arterial concentration and arterial-venous differences of glutamine across the kidney, forearm, hepato-splanchnic bed and brain were measured in patients with chronic renal insufficiency and in patients with normally functioning kidneys before and during chronic ammonium chloride acidosis. 2. In chronic renal insufficiency and in chronic metabolic acidosis there is a rise in glutamine release from the muscles and a suppression of glutamine uptake by the hepato-splanchnic bed and the brain. 3. In chronic renal insufficiency arterial glutamine concentrations is significantly increased in comparison with subjects with normal renal function and either normal acid-base balance or chronic metabolic acidosis. 4. In patients with chronic renal insufficiency the kidney extracts negligible amounts of glutamine, which cannot account for the renal ammonia production measured in the same patients.
Clin Sci Mol Med 1978 Oct
PMID:Effects of chronic renal insufficiency and metabolic acidosis on glutamine metabolism in man. 71 53

A mixture of ammonium palmitate, 14C-sn-glycero-1(3)-phosphate, cyanimide and imidazole when heated for several hours formed significant quantities of phospholipids. These reaction products were shown by chromatographic, chemical and enzymatic procedures to be monopalmitoylglycerophosphate (MPGP), dipalmitoylglycerophosphate (DPGP) and monopalmitoyl cyclic glycerophosphate (cMPGP). A portion of the MPGP and DPGP possessed the same steric configuration as naturally occurring lysophosphatidic acid and phosphatidic acid. The yield of total phospholipid was maximal at temperatures between 60 degrees and 90 degrees after 8 h. When ratios of reactants were varied, up to 45% of radioactive glycerophosphate was converted into phospholipids. The average proportions of individual phosphatidic acids were: 60% MPGP, 27% DPGP and 13% cMPGP. Evidence was obtained for a synergistic relationship between cyanamide and imidazole in promoting the formation of phosphatidic acids. These results suggest that phosphatidic acids, which are essential precursors for the biochemical synthesis of more complex membrane phospholipids, could have been produced on the primitive Earth.
J Mol Evol 1978 Oct 06
PMID:Cyanamide mediated syntheses under plausible primitive earth conditions. V. The synthesis of phosphatidic acids. 72 5

Two new classes of organic microspheres are described. One of them (melanoidin) is synthesized from amino acids and sugars in heated aqueous solutions. The other (aldocyanoin) is formed in aqueous solutions of ammonium cyanide and formaldehyde at room temperature. The general properties of these microspheres, including conditions of synthesis, size and shape, mechanical and pH stability, and solubility, are compared with corresponding properties of other "protocell" model systems. It is concluded that melanoidin and aldocyanoin microsphreres are plausible candidates for precellular units in the primitive hydrosphere. Since the bulk of the organic carbon in early Precambrian sediments is insoluble kerogen-melanoidin, it is suggested that some Precambrian "microfossils" may be abiotic melanoidin microspheres of the type described herein.
J Mol Evol 1976 Apr 09
PMID:Melanoidin and aldocyanoin microspheres: implications for chemical evolution and early precambrian micropaleontology. 77 93

Mutants of A. nidulans at several loci lack detectable NADPH-nitrate reductase activity. These loci include niaD, the structural gene for the nitrate reductase polypeptide, and five other loci termed cnxABC, E, F, G and H which are presumed to be involved in the formation of a molybdenum-containing component (MCC) necessary for nitrate reductase activity. When forzen mycelia from A. nidulans deletion mutant niaD26 were homogenized in a Ten Broeck homogenizer together with frozen mycelia from either cnxA6, cnxE29, cnsF12, cnxG4 or cnxH3 strains grown on urea + nitrate as the nitrogen source, nitrate reductase activity was detectable in the extract. Similar results were obtained by co-homogenizind niaD mycelia with Neurospora crassa nit-1 mycelia induced on nitrate. Thus, all A. nidulans cnx mutants are similar to the N. crassa nit-1 strain in their capacity to yield NADPH-nitrate reductase in the presence of the presumed MCC. As judged by the amounts of nitrate reductase formed, niaD26 mycelia grown on urea +/- nitrate contained much more available MCC than ammonium-grown mycelia. No NADPH-nitrate reductase activity was found in extracts prepared by co-homogenizing mycelia from all five A. nidulans cnx strains. Wild-type A. nidulans NADPH-nitrate reductase acid dissociated by adjustment to pH 2.0-2.5 AND RE-ADJUSTED TO PH 7 could itself re-assemble to form active nitrate reductase and thus was not a useful source of MCC for these experiments. These results are consistent with the conclusion that the active nitrate reductase complex is composed of polypeptide components which are the niaD gene product, plus the MCC which is formed through the combined action of the cnx gene products. Further, the production of MCC may be regulated in response to the nitrogen nutrition available to the organism.
Mol Gen Genet 1976 Dec 08
PMID:Formation of NADPH-nitrate reductase activity in vitro from Aspergillus nidulans niaD and cnx mutants. 79 78

A method for the isolation of highly active Escherichia coli ribosomal subunits has been described and used to obtain 30S subunits, which are fully active in the cistron-specific binding of tRNA, and reassociated 70S ribosomes, which are at least 35% active in the synthesis of polypeptides. The dissociation constants (Kd) of the 30S-poly(U)-tRNAPhe complex, which proved to be practically identical for tRNAPhe in the deacylated and aminoacylated forms, as well as for the chemically synthesized peptidyl-tRNA, have been measured. Changes in the binding conditions (temperatures from 0 to 30 degrees, Mg2+ concentrations from 20 to 5 mM, and NH4+ concentrations from 200 to 50mM) have a significant effect on the value of Kd without altering the number of active 30S subunits. It has been shown that the codon-specific binding of tRNA to the 30S subunits is completely reversible. The 30S subunits are not only not inactivated after a single act of binding of a tRNA molecule, but are capable of undergoing this process repeatedly without any appreciable loss in activity.
Mol Biol (Mosk)
PMID:Isolation and study of some properties of the highly active 30S and 50S Escherichia coli ribosomal subunits. 79 55

Addition of the bifunctional cations, bis(2-aminoethyl) disulphide-cystamine, and bis(2-guanidoethyl) disulphide-GED, into water solution of DNA results in a decrease in magnitude of the positive circular dichroism (CD) band. However, unlike the similar effect due to alcaline ions or ions of ammonium and guanidinium the above effect occurs at much smaller, stoichiometric with phosphates, concentrations of the dications. Another peculiarity of GED is the attaining of a plato region for the curve of the CD change with the rise of GED concentration. Since the decrease in positive band CD is connected with increase in the rotation angle between the base pairs, the observed behavior of the bifunctional cations are supposedly due to peculiarities of their winding action upon DNA helix. Reducing the disulphide bond in the cations gives rise to increase in the DNA positive CD band up to the values inherent to those in the presence of the corresponding monocations. The higher efficiency of the bifunctional cations is thus due to the cationic groups belong to one and the same molecule. Such compounds could thus be considered as a simple model of DNA-protein interaction.
Mol Biol (Mosk)
PMID:[Peculiarities of DNA winding with bifunctional cations]. 80 78

Oligomerization of 5' -TMP in water pools entrapped by dodecyl-ammonium chloride surfactant aggregates in benzene: hexane in the presence of dicyanodiimide at temperatures ranging from 21 degree -72 degree resulted in the formation of linear and cyclic oligonucleotides containing up to pentamers. Effects of temperature, time and surfactants have been examined. Rate constants for the formation of oligomers have been determined at five different temperatures. These data afforded values of (formula: see text). Prebiotic significance of these results are discussed.
J Mol Evol 1977 May 13
PMID:Novel prebiotic systems: nucleotide oligomerization in surfactant entrapped water pools. 86 24

1. The mechanism of potassium transport across human distal colon was investigated in twenty-two individuals without evidence of bowel disease, by using a dialysis method in conjunction with measurements of the transepithelial potential difference (p.d.). 2. Whether potassium was absorbed or secreted depended on its initial concentration in the lumen. The potassium net flux was approximately zero when the luminal potassium concentration was between 30 and 50 mmol/l. 3. Potassium secretion rate was little affected by sodium absorption rate, or by the luminal sodium concentration or by the osmolality of the luminal solution. 4. Potassium secretion rate was increased by partial substitution of other cations for sodium, in the descending order Li greater than NH4 greater than Rb greater than Na. Potassium concentration increased on average to over 80 mmol/l when lithium was in the lumen. 5. The observed transepithelial p.d. was inadequate to account for the intraluminal potassium concentrations attained, the discrepancy being most marked when ammonium or lithium was in the lumen. It is suggested that some potassium is secreted by the epithelial cells and this component of the total potassium flux into the lumen is increased when rubidium, ammonium or lithium is substituted for sodium.
Clin Sci Mol Med 1976 Sep
PMID:Potassium transport across the distal colon in man. 96 58

Two approaches may be used to study the function of cytochrome P-450 in insects: (a) an evaluation of the spectral and catalytic properties of the hemoprotein while associated with microsomal membranes; (b) the solubilization, resolution and purification of the microsomal mixed-function oxidase system. The first approach has provided some understanding of the biochemical factors involved in the metabolism of a variety of compounds, including pesticides, drugs, hormones and many other xenobiotics. However, solubilization of the monooxygenase system allows the study of each of its components individually, providing a better insight on the sequence of events leading to the hydroxylation of a substrate, the type of intermediates formed, and the rate-limiting step(s). This report discusses studies carried out with the monooxygenase system associated with microsomal membranes, as well as procedures to solubilize and partially purify its components from housefly microsomes. The latter involves solubilization with either Triton X-100 or sodium cholate, followed by either ammonium sulfate fractionation, Sephadex G-200, DEAE-Sephadex A-50 column chromatography or by omega-amino-n-octyl-Sepharose 4B affinity chromatography. These procedures have shown that two cytochrome P-450 species (P-450 and P-450I) are present in microsomes isolated from a resistant housefly strain. Induction with either naphthalene or phenobarbital appears to increase cytochrome P-450I preferentially.
Mol Cell Biochem 1976 Jul 30
PMID:Insect cytochrome P-450. 96 61

The primary structure of the major component of human skeletal muscle troponin C has been established. The troponin C was purified by ammonium sulphate and isoelectric fractionation, followed by two chromatographic steps on DEAE Sephadex. The sequence was determined from the different overlapping enzymic peptides and by dansyl-Edman degradation. The only difference between rabbit skeletal muscle troponin C and the major component of human skeletal troponin C was found at position 112: Ala (rabbit), Pro (human). The partial amino acid sequence of the first 86 residues of the minor component of human skeletal troponin C was found to resemble the troponin C from bovine cardiac muscle. The only difference between them, has tentatively been located at position 62: Glu (human), Asp (bovine). These similarities suggest that troponin C is, from the point of view of molecular, one of the most conservative proteins so far studied.
J Mol Evol 1976 Oct 27
PMID:Human skeletal muscle proteins. The primary structure of troponin C. 97 49


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