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. A group of patients with essential hypertension was divided into three categories on the basis of the plasma renin activity. 2. There was no correlation between the plasma renin activity categorized as high, normal or low and the duration of hypertension, the incidence of left ventricular enlargement, the blood urea nitrogen, serum creatinine, cholesterol or uric acid respectively. 3. Analysis of data showed that the incidence of cardiovascular events in the hypertensive population correlated with the plasma renin activity only in combination with known risk factors.
Clin Sci Mol Med Suppl 1975 Jun
PMID:Plasma renin activity and cardiovascular disease. 107 64

Mutants, designated tamAr, have been isolated on the basis of simultaneous resistance to toxic analogues thiourea, aspartate hydroxamate and chlorate with L-alanine as the sole nitrogen source. tamAr mutants are also resistant to methylammonium. This resistance of tamAr mutants is correlated with partially repressed activity of a number of enzyme and transport systems regulated by ammonium. Furthermore, tam-Ar mutants have low NADP-glutamate dehydrogenase (NADP-GDH) activity and also efflux ammonium under certain growth conditions. Mutants at the areA locus (areAr) have also been isolated on the basis of resistance to these analogues, with nitrate or L-aspartate as the nitrogen source. These, similar to tamAr lesions, result in resistance to methylammonium and are partially repressed for ammonium repressible system, but in contrast to tamAr, areAr alleles have wild-type NADP-GDH activity and normal ammonium efflux. tamAr and areAr mutants grow as wild type on all nitrogen or carbon sources tested, are recessive, and appear to be epistatic to all other mutations (gdhA1, meaA8 and meaB6) which result in derepressed levels of ammonium regulated system. Whereas tamAr and areAr phenotypes are additive, tamAr is epistatic to areAd phenotype.
Mol Gen Genet 1975 Sep 29
PMID:Studies of partially repressed mutants at the tamA and areA loci in Aspergillus nidulans. 110 54

1. The cardiogenic oscillations in the concentration of nitrogen and argon in expired gas, which are seen after the inspiration from residual volume of pure oxygen or a bolus of argon, have been studied in normal subjects and in patients with atrial fibrillation. 2. In the upright position of the subject, the peaks of nitrogen and argon concentration coincide with ventricular systole, although there is a transit delay along the tracheobronchial tree before any change of concentration occurs at the mouth. 3. Studies in different postures demonstrated that the effect of the heart is predominantly due to a reduction in cardiac volume during systole with a decrease in airflow from regions adjacent to the heart. These areas contain a different concentration of nitrogen and argon in the alveolar air from the more apical regions. 4. It has been shown that the results are consistent with the present concepts of the influence of gravity on the distribution of inspired air.
Clin Sci Mol Med 1975 Jan
PMID:Cardiogenic oscillations of nitrogen and argon concentration in expired gas in man. 111 79

1. The relation between endogenous urea metabolism and albumin synthesis has been studied in ten patients with chronic renal failure and in four normal subjects, after single intravenous injections of [14-C]urea,[15-N]urea and 125-I-labelled albumin. 2. The rate of urea synthesis was determined from the dynamics of plasma [14-C]urea specific radioactivity and the rate of urea metabolism was estimated from the relative rates of urea synthesis and urea appearance in urine and body water. Deconvolution analysis of plasma [15N]albumin enrichmevt and 125-i-labelled albumin radioactivity yielded the cumulative incorporation of 15-N into total exchangeable albumin and enabled calculation of the absolute rate of urema nitrogen utilization for albumin synthesis. 3. Although the mean absolute rate of urea degradation in uraemic patients (3-7 mmol/h) was higher than in normal subjects (2-3 mmol/h) there was no significant positive correlation between urea degradation and plasma urea concentration. 4. In uraemic subjects, there was a significant positive correlation between urea synthetic rate and urea degration rate. 5. The rate of utilization of urea nitrogen for albumin synthesis was low, but was very much higher in uraemic subjects (mean 83-8 mumol/h) compared with normal subjects (mean 6-4 mumol/h), as was the provision by urea of the nitrogen required for albumin synthesis in uraemic subjects (2-37%) compared with normal subjects (0-13%). 6. The efficiency of utilization of urea nitrogen for albumin synthesis was higher in the uraemic patients (1-3%) than the normal subjects (0-2%), and was higher in those patients with chronic renal failure who received a 30 g protein diet than those on 70 g of protein. A significant negative correlation was noted between efficiency of urea nitrogen utilization and the rate of synthesis of albumin. 7. These studies suggest the presence of a mechanism for the conservation of urea nitrogen in chronic renal failure which is unrelated to the extent of urea degradation, and which can only be partly explained by the higher proportion of intraluminal gut nitrogen derived from urea.
Clin Sci Mol Med 1975 May
PMID:Efficiency of utilization of urea nitrogen for albumin synthesis by chronically uraemic and normal man. 112 30

The major photoproduct obtained on irradiation of gaseous NH3 and CO mixtures is ammonium cyanate; lesser amounts of urea, biurea, biuret semi-carbazide, formamide and cyanide were observed. The formation of the major gas phase photolysis product may be rationalized by the following reaction sequence: (see article). Urea is probably formed from NH4NCO in a thermal reaction while formamide may result from the disproportionation of NH2CO. Photocatalytic syntheses of 14C-urea, -formamide, and -formadehyde are effected by irradiation of 14CO and NH3 in the presence of Vycor, silica gel, or volcanic ash shale surfaces. These syntheses are catalyzed by ultraviolet wavelengths longer than those absorbed by the gaseous reactants. The syntheses are also effected when the surface material is first irradiated in the presence of CO followed by a dark incubation with NH3. Apparently, the initiating step is a light dependent formation of a reactive form of CO on the surface. A discussion is given on the possible contribution of these reactions to the abiotic synthesis of organic nitrogen compounds on Mars, on the primitive Earth and in interstellar space.
J Mol Evol 1975 Aug 05
PMID:Ultraviolet-gas phase and -photocatalytic synthesis from CO and NH3. 115 1

1. Five healthy male subjects were studied by continuous infusion of L-[alpha-15N]lysine over 20-30 h with timed blood and urine samples, and two or three percutaneous needle biopsies of vastus lateralis muscle. 2. A standard creatine-free diet, quantitatively related to body surface area, was given for 5 days before the infusion. The [15N]lysine was administered at a constant rate in an amino acid solution with a nitrogen content of 0-96 mol/l, which constituted the sole source of exogenous nitrogen during the infusion. 3. A plateau level of plasma free [15N]lysine enrichment was achieved after infusion for 14 h. The total plasma lysine flux calculated from the plateau was 7-3 mmol/h (range 4-8-9-6). Total body protein turnover calculated from the lysine flux was 3-5 g day-1 kg body wt.-1 (range 2-5-5-0). 4. Muscle sarcoplasmic and myofibrillar fractions were separated, purified and the 15N enrichment was measured. The sarcoplasmic protein fractional synthetic rate was calculated as 3-8%/day (range 2-2-5-1). The myofibrillar protein synthetic rate was 1-46%/day (range 1-09-2-44). 5. Muscle mass, calculated from 24 h creatinine excretion, was 33-7 kg (range 28-8-37-4), which represented 50-0% of body weight (range 38-9-58-1). Total muscle protein synthesis was calculated to account for 53-2% (range 39-5-62-1) of total body protein syntehsis. 6. The advantages and limitations of using continuous infusion of [15N]lysine in human subjects are discussed.
Clin Sci Mol Med 1975 Dec
PMID:Measurement of muscle protein synthetic rate from serial muscle biopsies and total body protein turnover in man by continuous intravenous infusion of L-(alpha-15N)lysine. 120 89

Conformational possibilities of pirrolidine analogues of acetylcholine beta-(N-methyl pirrolidinium)-ethyl ester of acetic acid and beta-(N-ethyl pirrolidinium)-ethyl ester of acetic acid and beta-(N-ethyl pirrolidinium)-ethyl ester of acetic acid were investigated by the method of atomic potentials. The conformational energy was considered as a sum of non-bonded and electrostatical interactions, torsional energy and distortions of bond angles. It has been shown that the replacement of the nitrogen methyl group to ethyl group results in decrease of the average barrier height between two gauche conformations of the O--C--C--N fragment. Comparison of conformational properties of some cholinesterase substrates permit to draw a suggestion that the barrier height influences the rate of the enzymatic hydrolysis.
Mol Biol (Mosk)
PMID:[A theoretical conformational analysis of several substrates of cholinesterase having a cyclic ammonium group structure]. 122 66

We report here the transcriptional analysis of the fixABCXORF1 region of Azorhizobium caulinodans. This led to the identification of a 0.9 kb transcript covering fixX and ORF1, which was synthesized only under conditions of nitrogen fixation. The 5' end of this transcript was mapped by primer extension and S1 nuclease protection analyses and shown to be located 70 +/- 1 nucleotides upstream of the fixX start codon. By means of transcriptional fixX- and ORF1-lacZ fusions, it was shown that fixX and ORF1 were most probably transcribed from the fixA promoter and that expression of fixX and ORF1 was dependent on NifA activation. This suggests that the 0.9 kb mRNA results from post-transcriptional processing of a large mRNA covering fixA,B,C,X and ORF1. In addition, ORF1 mutants were constructed and were shown not to be impaired in nitrogenase activity.
Mol Gen Genet 1992 Nov
PMID:Transcriptional analysis of the fix ABCXORF1 region of Azorhizobium caulinodans suggests post-transcriptional processing of the fix ABCXORF1 mRNA. 128 16

Two new continuum solvation models have been presented recently, and in this paper they are explained and reviewed in detail with further examples. Solvation Model 2 (AM1-SM2) is based on the Austin Model 1 and Solvation Model 3 (PM3-SM3) on the Parameterized Model 3 semiempirical Hamiltonian. In addition to the incorporation of phosphorus parameters, both of these new models address specific deficiencies in the original Solvation Model 1 (AM1-SM1), viz., (1) more accurate account is taken of the hydrophobic effect of hydrocarbons, (2) assignment of heavy-atom surface tensions is based on the presence or absence of bonded hydrogen atoms, and (3) the treatment of specific hydration-shell water molecules is more consistent. The new models offer considerably improved performance compared to AM1-SM1 for neutral molecules and essentially equivalent performance for ions. The solute charges within the Parameterized Model 3 Hamiltonian limit the utility of PM3-SM3 for compounds containing nitrogen and possibly phosphorus. For other systems both AM1-SM2 and PM3-SM3 give realistic results, but AM1-SM2 in general outperforms PM3-SM3. Key features of the models are discussed with respect to alternative approaches.
J Comput Aided Mol Des 1992 Dec
PMID:AM1-SM2 and PM3-SM3 parameterized SCF solvation models for free energies in aqueous solution. 129 30

We report here a theoretical study of a series of fentanyl analogs with a wide range of affinities and selectivities at the mu receptor, designed to identify and characterize the molecular determinants of mu receptor recognition. In this work, a complete conformational search combining nested rotations and molecular dynamic simulations has been made, leading to identification of accessible conformers for all analogs and to the selection of a candidate bioactive form. In addition, electronic properties have been calculated and examined as possible modulators of recognition at the mu receptor. The results of these studies have led to a distinct pharmacophore for interaction at the mu receptor for this class of compounds, with the piperidine ring in a chair conformation and the N-phenethyl and 4-phenylpropanamide substituents both equatorial. Moreover, four key moieties necessary for optimum receptor recognition and a postulated role for each of them in this recognition have been identified. These are (i) a protonated amine nitrogen, assumed to be involved in an initial electrostatic interaction with a negatively charged site on the receptor; (ii) a polar function capable of hydrogen-bonding with an electrophilic site; (iii) an aromatic ring involved in lipophilic interaction with a similar moiety; and (iv) a second aromatic ring, most probably involved in electron transfer interaction with the receptor. These requirements, taken together, form the basis of our proposed mechanism for mu receptor recognition. Not only is the presence of these components required for recognition, but specific steric relationships between them have been determined, implying the appropriate arrangement for interaction with complementary receptor sites. These steric parameters are pseudobond angles and one torsion angle that determine the relative spatial arrangement of these four moieties. They are the angles theta 1 and theta 3, defining the relative position of the protonated nitrogen and the polar function with each of the two aromatic rings, and the torsion angle eta 1, defining the orientation of the lone pair(s) on the polar proton-accepting function with respect to the lone pair on the piperidine nitrogen. This postulated mechanism of recognition provides a conceptual framework to understand why some compounds do and some do not recognize the mu receptor.
Mol Pharmacol 1992 Jan
PMID:Molecular determinants of mu receptor recognition for the fentanyl class of compounds. 131 Jan 42


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