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. Free amino acids were determined in the plasma and in the muscle tissue of 14 patients with chronic uraemia; eight were not on dialysis and six were having regular peritoneal dialysis. The concentration of each amino acid in muscle water was calculated with the chloride method. 2. In both groups of patients there were low intracellular concentrations of threonine, valine, tyrosine and carnosine, and high glycine/valine and phenylalanine/tyrosine ratios. Both groups of patients had increased amounts of 1- and 3-methyl-histidine in plasma and in muscle water. 3. The non-dialysed patients had low intracellular concentrations of lysine, and the dialysed patients had high intracellular concentrations of lysine, isoleucine, leucine and of some of the non-essential amino acids. 4. After peritoneal dialysis for 22 h, the plasma concentration of several amino acids decreased but the intracellular concentrations of most amino acids did not change significantly. 5. Intravenous administration of essential amino acids and histidine during the last 4 h of dialysis increased in muscle the total free amino acids, the ratio of essential to non-essential amino acids and the valine and phenylalanine concentrations. 6. The results demonstrated that the plasma and muscle concentrations of several amino acids are grossly abnormal in chronic uraemia. Non-dialysed and dialysed patients exhibit important differences, especially in the intracellular amino acid patterns. Infusion of essential amino acids may result in enhancement of protein synthesis.
Clin Sci Mol Med 1978 Jan
PMID:Intracellular free amino acids in muscle tissue of patients with chronic uraemia: effect of peritoneal dialysis and infusion of essential amino acids. 62 Apr 93

1. Venous blood concentrations of the branched-chain amino acids, valine, leucine and isoleucine, and urinary nitrogen excretion have been measured in sixteen adult males, from 2 h to 7 days after injury, and in four adults after elective skin grafts. 2. In the injured group the concentrations of these amino acids rose significantly 24 h after injury and had doubled at 4 days and remained high; in contrast the skin-graft patients showed no significant change. 3. In those injured patients with initial hyperketonaemia, defined as more than 0-2 mmo1/1, the increase in concentrations of branched-chain amino acids at the fourth and seventh days after injury was significantly less than in those with normoketonaemia, and was accompanied by lower urinary nitrogen excretion throughout the whole period. 4. It is suggested that the changes in the concentration of branched-chain amino acids after injury indicate decreased uptake by muscle or excessive release due to an imbalance between protein synthesis and protein catabolism in this tissue.
Clin Sci Mol Med 1976 May
PMID:Branched-chain amino acids, nitrogen excretion and injury in man. 77 95

The mutant T44(lambda) of Escherichia coli K12, grown in the presence of adenine, develops an increased tolerance to streptomycin. In cultures grown on streptomycin, the ts character (tif) may temporarily be suppressed but, on further transfer, both the temperature-sensitive phenotype and streptomycin tolerance disappear. In a cell-free system, the relative efficiency of translation of MS2 and poly U messenger RNAs was, respectively, 75 and 50% lower in extracts from cultures grown at 37 degrees with adenine than in extracts from 30 degrees cultures. Similar results were obtained when adenine was added in vitro to an extract from a culture grown at 37 degrees in the absence of adenine, using MS2 RNA as messenger. Moreover, the 37 degrees extracts showed a much lower misincorporation of isoleucine into polyphenylalanine in the poly U system. In addition, the Mg++ concentration required for optimal translational acitvity was higher for the 37 degrees than for the 30 degrees extracts. Extracts from a culture grown in L medium at 37 degrees or from a tif-/F'tif+ merodiploid grown at 37 degrees with adenine behaved similarly to that from the 30 degrees culture when poly U was used as messenger RNA. It is suggested that the tif+ gene product may play a regulatory role in ribosomal function and the pleiotropic nature of the tif-1 mutation could be due to impairment of translational activity augmented by elevated temperature or by adenine.
Mol Gen Genet 1976 Aug 10
PMID:Phenotypic instability in a tif-1 Mutant of Escherichia coli. I. Impairment in ribosomal function. 78 26

A series of Mu-1 induced isoleucine and valine auxotrophs derived from the wild type K-12 strain of Escherichia coli and from a valine resistant (ilvO-) mutant were examined. It was concluded that the genes ilvE, ilvD and ilvA constitute a single operon and are transcribed from E to A. Furthermore, the ilvG gene, expressed only in ilvO- strains, does not lie between ilvE and ilvD as previously assumed. A mutation in rho was examined for its effect on the ilvEDA operon. One effect of the rho- mutation was a mimicking of an isoleucine limitation signal. A model for the regulation of the ilvEDA operon is discussed. The model involves multiple attentuation sites and a possible role for the ilvO locus which lies at the distal end of the ilvEDA operon (but is not part of it). Supportive evidence for the proposed direction of transcription was obtained by examination of a series of gammailv transducing phages.
Mol Gen Genet 1976 Oct 18
PMID:Polarity and the regulation of the ilv gene cluster in Escherichia coli strain K-12. 79 Jan 50

1. The characteristics of absorption of individual amino acids from amino acid mixtures simulating casein and from enzymic hydrolysates of casein containing oligopeptides as well as free amino acids are known to be different. The differences, which are attributable to mucosal uptake of small peptides, involve more rapid absorption from the enzymic hydrolysates of certain amino acids which are relatively slowly absorbed from the amino acid mixtures. This could lead to more effective utilization of amino acids from the enzymic hydrolysates than from the amino acid mixtures. 2. To obtain further information bearing on this hypothesis, we have used a recently developed technique for portal cannulation in the guinea pig to make a preliminary investigation of amino acid concentrations in the portal venous plasma at intervals after the infusion into the duodenum of equivalent amounts of (a) an amino acid mixture simulating casein and (b) a partial enzymic (papain followed by kidney peptidases) hydrolysate of casein, the two preparations being infused in separate experiments. 3. For some amino acids, such as leucine, isoleucine, valine, phenylalanine and lysine, the curves after the enzymic hydrolysate were fairly similar to the corresponding curves after the amino acid mixture, though usually slightly lower. With other amino acids, the curves after the enzymic hydrolysate were very much lower than the corresponding curves after the amino acid mixture. With serine, glutamine, proline and glycine this discrepancy was particularly great. 4. The results cannot yet be fully explained, but their main features are explicable by the hypothesis that the lower amino acid concentrations in portal plasma after the enzymic hydrolysate are the result of entry of amino acids into the portal blood in peptide form, in which they would not be detectable by the analytical technique employed, and possibly also of more rapid clearance of amino acids from the blood during absorption of this preparation.
Clin Sci Mol Med 1977 Mar
PMID:Amino acid concentrations in portal venous plasma during absorption from the small intestine of the guinea pig of an amino acid mixture simulating casein and a partial enzymic hydrolysate of casein. 84 57

1. A jejunal perfusion technique has been used in normal volunteer subjects to study jejunal absorption of amino acid residues from a partial enzymic hydrolysate of casein in which about 50% of the amino acids existed as small peptides, and also from an equivalent mixture of free amino acids. 2. The effect of a high concentration of the dipeptide glycylglycine on the absorption of amino acid residues from these preparations was studied to quantify the importance of mucosal uptake of intact peptides during absorption of the partial hydrolysate of casein. 3. The results were unexpected. Glycylglycine significantly inhibited absorption of several amino acid residues (aspartic acid + asparagine, serine, glutamic acid + glutamine, proline, alanine, phenylalanine, threonine and isoleucine) from the free amino acid mixture, whereas it significantly inhibited the absorption of only two (serine, glutamin acid + glutamine) from the peptide-containing partial casein hydrolysate. 4. The effect of glycylglycine on absorption of amino acids from the mixture of free amino acids was apparently due to inhibition of amino acid uptake by free glycine liberated from the dipeptide during perfusion. The reason for the failure of glycylglycine to cause extensive inhibition of absorption from the partial hydrolysate is not clear. It may be due to glycylglycine being only a weak inhibitor of peptide uptake, but the possibility that some peptides are taken up by a system unavailable to glycylglycine has to be considered.
Clin Sci Mol Med 1977 Jul
PMID:Effect of glycylglycine on absorption from human jejunum of an amino acid mixture simulating casein and a partial enzymic hydrolysate of casein containing small peptides. 87 18

1. The angiotensin II antagonism by newly synthesized 8-C-phenylglycine analogues of [5-isoleucine]angiotensin II in different preparations was investigated in vitro and in vivo. 2. All analogues competitively inhibited the myotropic effect of angiotensin II on the isolated colon ascendens of the guinea-pig and the stomach of the rat. 3. In normotensive dogs, cats, rabbits, guinea-pigs and rats the blood pressure response to infused angiotensin II was inhibited by the antagonists. The angiotensin II-induced fall in renal blood flow in the dog was blocked during infusion of the analogues. Acute renal hypertension in rats was significantly decreased. Of conscious rats variously with normal blood pressures, spontaneous hypertension and chronic renal hypertension, only in the last group could a marked uniform fall in blood pressure be demonstrated. The central pressor effect of angiotensin II was also inhibited in conscious rats. 4. 8-C-Phenylglycine analogues of [5-isoleucine]-angiotensin II exhibit a specific antagonistic activity to endogenous and exogenous angiotensin II.
Clin Sci Mol Med Suppl 1975 Jun
PMID:Comparative pharmacology of new specific angiotensin antagonists. 107 69

Hybridization of messenger ribonucleic acid (mRNA) isolated from Escherichia Coli K-12 to deoxyribonucleic acid (DNA) from lambdaCI857st68h80dilv was used to detect isoleucine-valine (ilv) specific mRNA. A number of strains partially constitutive for the isoleucine-valine enzymes had levels of ilv mRNA 2 to 3-fold higher than the parent strain. Starvation for any of the branched-chain amino acids resulted in a 20 to 23-fold increase in ilv mRNA as compared to repressed levels. These differences were not due to altered growth rates or to changes in the stability of ilv mRNA. These data indicate that regulation of the isoleucine-valine enzymes by multivalent repression occurs mainly at the level of transcription. Kinetics of elongation of ilv mRNA after repression are consistent with the assumption that the mechanism of multivalent repression involves the prevention of further initiations by RNA polymerase.
Mol Gen Genet 1975 Jun 19
PMID:Transcriptional control of the isoleucine-valine messenger RNA's in E. coli K-12. 110 33

Cationic amino acids, arginine and lysine partition differentially from water into aqueous micellar sodium dodecanoate. Conversely, partitioning of serine, glycine, aspartic acid, glutamic acid, threonine, alanine, proline, valine, leucine, phenylalanine and isoleucine do not vary appreciably. Partitioning from neat hexane into dodecylammonium propionate trapped water in hexane is, however, dependent upon both electrostatic and hydrophobic interactions. These results imply that the interior of dedecylammonium propionate aggregates is negatively charged and is capable of hydrogen bonding in addition to providing a hydrophobic enviroment. The solubilities of amino acids in neat hexane substantiate the previously derived amino acid hydrophobicity scale. Relevance of partitioning in these systems to the postulated selective amino acid compartmentalization is discussed.
J Mol Evol 1975 Nov 04
PMID:Compartmentalization of amino acids in surfactant aggregates. Partitioning between water and aqueous micellar sodium deodecanoate and between hexane and dodecylammonium propionate trapped water in hexane. 120 27

The cytochrome c oxidase subunit I (COI) gene sequences from planarian (Dugesia japonica) DNA, most probably of mitochondrial origin, are heterogeneous. Taking advantage of the heterogeneity that occurs primarily in silent sites of the COI DNA sequences, amino acid assignments of several codons have been deduced as nonuniversal: UGA = Trp, AAA = Asp, and AGR (R: A or G) = Ser. In addition, UAA, a stop codon in the universal genetic code, is tentatively assumed to be a tyrosine codon, because three of the sequences examined have UAA at the well-conserved tyrosine site of UAY (Y: U or C) in other planarian sequences as well as in the mitochondria of human, Xenopus, sea urchin, Drosophila, Trypanosoma, and Saccharomyces cerevisiae. AUA would most probably be an isoleucine codon in these mitochondria, whereas it is a methionine codon in the majority of nonplant mitochondria.
J Mol Evol 1992 Apr
PMID:Planarian mitochondria. II. The unique genetic code as deduced from cytochrome c oxidase subunit I gene sequences. 131 9


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