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)

The formation of glycerol occurs when a solution of DL-glyceraldehyde is heated in the presence of hydrogen sulfide at room temperature. DL-glyceraldehyde and dihydroxyacetone treated with hydrazine, as well as DL-glyceraldehyde incubated with formaldehyde are also partially converted to glycerol. The yields of the above reactions are from approximately 1% to about 3%. The formation of glycerophosphates occurs when glycerol is heated with ammonium dihydrogen phosphate and either urea or cyanamide. The yield of glycerophosphates is about 30%, most of which is sn-glycero-1 (3)-phosphate. These findings indicate that glycerol and sn-glycero-3-phosphate, which are moieties of glycerolipids, could have been formed under conditions which may have prevailed on the primitive Earth.
J Mol Evol 1979 Dec
PMID:Cyanamide mediated synthesis under plausible primitive earth conditions. VI. The synthesis of glycerol and glycerophosphates. 53 3

Partially purified flounder muscle (Pseudopleuronectus americanus) glyceraldehyde 3-phosphate dehydrogenase was immobilized on cyanogen bromide-activated Sepharose. The catalytic properties of the immobilized preparation were studied to determine if immobilization alters the kinetic properties of the native holoenzyme. The results indicate that the pH activity profile of immobilized glyceraldehyde 3-phosphate dehydrogenase did not differ from that of the native enzyme. The Michaelis constants (Km) for NAD and glyceraldehyde 3-phosphate were somewhat altered. The enzyme stability toward various inactivation treatments in the presence and absence of NAD was characterized and compared to that of he native enzyme. When either form of the enzyme was incubated with urea at concentrations greater than 2M, inactivation occurred very rapidly. Incubation in 0.1% trypsin for 60 minutes decreased the activity of immobilized glyceraldehyde 3-phosphate dehydrogenase by 45% and of the native soluble enzyme by 70%. The immobilized enzyme also exhibited considerably more stability than the native soluble enzyme when exposed to a temperature of 50 degrees or to 20 mM ATP. In all cases NAD either greatly reduced the rate of inactivation or completely protected the enzyme from inactivation.
Mol Cell Biochem 1978 Nov 16
PMID:Immobilized flounder muscle glyceraldehyde 3-phosphate dehydrogenase. 56 63

A new procedure is described for a large scale separation and purification of unfixed DNA and RNA from a mixture of partially extracted nucleic acids and lysates of subcellular fractions by centrifugation to equilibrium in cesium sulfate-urea mixture. Optimum conditions are described for the separation and quantative recovery of both RNA and DNA in a pure form. The procedure allows determination of peak buoyant densities of 4-5s RNA, 7-11s mRNA and total cytoplasmic RNA. The procedure also allows fractionation of small molecular weight classes of cytoplasmic RNAs from the 18s and 28s rRNAs.
Mol Biol Rep 1978 Feb 28
PMID:Preparative density gradient centrifugation of RNA and DNA in cesium sulfate-urea mixture. 64 42

Isotermic unfolding of ribonuclease A, phosphopyridoxyl-8Lys41-RNAase A and complexes of the enzyme with cytidine, 2'-CMP, 3'-CMP, 3'-AMP and with the phosphoric ester of 1-(omega-oxypropyl)-cytosine in presence of urea has been studied. The stabilization of the protein structure resulting from the complex formation was shown to be determined by the ligand nucleobase binding. The comparison of the results obtained with those known from the literature suggests, that binding and catalytic zones of the enzyme active site form an integrated network system which is substained by multipoint contacts between the constituents. The change in the state of any part within the enzyme active state affects the energetics of the whole protein globule.
Mol Biol (Mosk)
PMID:[Conformational stability of ribonuclease A complexes with specific inhibitors]. 66 25

1. The placental transfer of urea was studied by perfusing the guinea-pig foetal placenta in situ with dextran solutions containing various amounts of urea, and radioactively labelled urea. 2. Transfer of urea was linearly related to the difference in concentration between the maternal and the foetal sides of the placenta, but transfer in both directions across the placenta was equal when the concentration of urea in the perfusing fluid was 2.5--3.5 mmol/l less than the maternal arterial value. This suggested that urea may be transferred against a concentration gradient. 3. Foetal plasma urea concentrations were found to be 0.5 mmol/l less than the maternal, suggesting that active transfer from the foetal circulation to the maternal can occur. However, because of the close relationship between foetal and maternal plasma urea (r = 0.96), it is concluded that the major control of foetal urea concentrations is by diffusion of urea between maternal and foetal extracellular fluids.
Clin Sci Mol Med 1978 Oct
PMID:Excretion of urea by the foetal guinea pig. 71 47

The effect of modification of photoreceptor membranes of the bovine retina on the termodynamical parameters that characterize heat denaturation of rodopsin was studied. The highest increase of the rate constant and the corresponding maximal drop of the free energy change of heat denaturation of the pigment were obtained by using 7 M urea or 25% Triton X-100 in the presence of 5.10(-4) M EDTA. After chipping off one third of the protein from the rodopsin molecule by papain treatment a significant decrease of the slope of the Arrenius curve and a maximal decrease of entropy change compared to the parameters known for heat denaturation of the pigment in native photoreceptor membranes were found. Modification of the lipid components of the photoreceptor membranes (treatment with Triton X-100 and phospholipase C) reduced the thermostability of rodopsin. Maximal changes were obtained at Triton X-100 concentrations 0.1--1%, further concentration increas (1--25%) did not lead to significant changes. Phospholipase C treatment resulted in a decrease of free energy change and an increase of entropy change without affecting entalpy changes, accompaning the heat denaturation of rodopsin. Bivalent cations (Ca2+, Mg2+) increased the termostability of rodopsin both in photoreceptor membranes and in solutions to 25% Triton X-100.
Mol Biol (Mosk)
PMID:[Modification of the retina photoreceptor membranes and temperature stability of rhodopsin]. 73 88

1. The effects of acute acid-base alterations on renal ammonia production and glutamine metabolism were studied in anaesthetized dogs. 2. Plasma glutamine rose with acidosis and also when both PCO2 and plasma HCO-3 were raised isohydrically. 3. Blood urea fell when acidosis was induced with hydrochloric acid. 4. The renal production of ammonia per ml of renal blood flow was increased in acidosis, but this was independent of the amount of glutamine delivered to the kidney. 5. The results indicate that acute acidosis affects production of urea and glutamine and increases the capacity of the renal cells to extract glutamine from blood.
Clin Sci Mol Med 1978 May
PMID:Effects of acute acid--base alterations on glutamine metabolism and renal ammoniagenesis in the dog. 75 Jan 52

1. In rats deprived of food and water for 24 h acute renal failure was produced by the intramuscular injection of glycerol. Eight hours later plasma urea concentration had increased threefold despite a small rise in urine volume. Plasma concentrations of renin and renin substrate were elevated. 2. When saralasin, a competitive antagonist of angiotensin II, was infused for 8 h after glycerol injection, urine volume and plasma urea were similar to values in rats that had received an infusion of saline. 3. Administration of rat serum (4.5 ml h-1 kg-1) for 4 h suppressed plasma renin concentrations, but plasma urea increased to the same extent as in rats without serum. 4. When saralasin and serum were infused at the same time, urine volume, urine osmolality and solute excretion increased and the rise of plasma urea was diminished. 5. Saralasin has a protective effect against glycerol-induced acute renal failure only when volume is replaced concomitantly.
Clin Sci Mol Med 1978 May
PMID:Effect of saralasin and serum in myohaemoglobinuric acute renal failure of rats. 75 Jan 57

Protein of purified 30S particles analyzed by sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis is present mainly as two bands with the apparent molecular weight of 38 000 and 41 000 daltons. These bands contain not less than 90% of the total protein. When the same material is electrophoresed in the presence of urea (pH 4.5) it migrates as one homogeneous band. The procedure for isolation of free informofers in preparative scale is described. The free informofers do not contain rapidly labeled RNA and are not stable: they dissociate reversibly into protein subunits of lower molecular weights. The dissociation is concentration dependent: low concentration of protein facilitates the dissociation process. Both whole informofers and their protein subunits easily interact with free pro-mRNA yielding 30S RNP. However only the product of reconstruction with informofers is similar to native 30S particles, according to several biochemical tests. These data support the model of the structure of nuclear RNP particles according to which pro-mRNA is distributed on the surface of globular protein particles.
Mol Biol (Mosk)
PMID:[Nuclear ribonucleoprotein particles containing messenger RNA. 12. Studies of dissociation and reconstruction of 30S particles]. 75 95

RNA polymerase of E. coli (EC 2.7.7.6) is able to bind certain oligoribonucleotides with the length greater than or equal to 5 from the corresponding isoplith mixtures (Knorre V.L., Vasilenko S.V., Salganik R.I., FEBS Letters 30, 229, 1973). It has been shown in this study that all pentaribonucleotides able to be bound by RNA polymerase can be extracted from the random mixture by the enzyme saturation procedure. Loosely and tightly bound pentaribonucleotides subfractions were isolated and each was separated by chromatography into 3-4 isopliths. Blocking of the enzyme SH groups by p-chloromercurium benzoate (10(-3) M) and denaturation by urea (6.3 M) prevent formation of the enzyme-pentaribonucleotides complexes. Complexes are destroyed by heat denaturation. Removal of sigma-subunit does not influence the enzyme capacity for pentaribonucleotides binding.
Mol Biol (Mosk)
PMID:[Conditions for specific oligoribonucleotide binding with E. coli RNA-polymerase]. 78 22


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