Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The alpha-isopropylmalate synthase (EC 4.1.3.12) from Alcaligenes eutrophus H 16 was inhibited by L-leucine and alpha-ketoisocaproate. The extent of inhibition was influenced by substrate- and inhibitor concentrations as well as by the pH. Intermediary plateaus, which always appeared in the inhibition curves, suggested cooperative effects. The maximal Hill coefficient was found to be two. At low concentrations of leucine the inhibition mechanism was of the competitive type with respect to substrate acetyl coenzyme A and of the noncompetitive type with respect to substrate alpha-ketoisovalerate. The inhibition was specifically relieved by the addition of valine or isoleucine. The anomalous effect of temperature on enzyme activity was diminished by leucine. The Arrhenius energy of the reaction increased from about 11 kcal/mole in the absence of leucine to about 18 kcal/mole in the presence of leucine. The further addition of valine reversed this effect. The physiological relevance of the alpha-ketoisocaproate-mediated inhibition is discussed.
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PMID:Alpha-isopropylmalate synthase from Alcaligenes eutrophus H 16. III. Endproduct inhibition and its relief by valine and isoleucine. 2 Aug 65

Indoleamine 2,3-dioxygenase was purified from rabbit small intestine to apparent homogeneity as judged by polyacrylamide gel electrophoresis and analytical ultracentrifugation. The native enzyme was a monomeric protein of a molecular weight of 41,000 +/- 1,000 with an s020,w value of 3.45 S. It had a relative abundance of hydrophobic amino acids such as valine, leucine, and isoleucine, and contained approximately 5% carbohydrate by weight. The estimated content of sugar residues per mol of enzyme was: galactose, 1.2; mannose, 2.6; N-acetylglucosamine, 5.2; and sialic acid, 0.8. One mole of enzyme had 0.8 mol of protoheme IX as a prosthetic group. However, copper was not detected in a significant amount and the ratio of copper to heme was less than 0.03. EPR spectra of the nitric oxide complex of the ferrous enzyme indicated that a nitrogen atom, possibly in an imidazole group, might be coordinated as the fifth ligand of the heme coenzyme. The anisotropic g values were gx = 2.08, gy = 1.98, and gz = 2.01. A single enzyme protein catalyzed the oxygenative ring cleavage of D- and L-tryptophan, D- and L-5-hydroxytryptophan, tryptamine, and serotonin. In addition, the purified enzyme had a peroxidase activity with guaiacol and potassium iodide as hydrogen donors, but not a catalase activity.
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PMID:Indoleamine 2,3-dioxygenase. Purification and some properties. 2 87

The purpose of the present study was to determine if the enoyl coenzyme A hydratase formed by Pseudomonas putida during growth on isoleucine was a unique enzyme specific for isoleucine metabolism. The highest levels of the hydratase were formed during growth on isoleucine intermediates and the lowest levels during growth on glutamate and glucose. Data from growth experiments revealed that 2-methyl-3-hydroxybutyryl coenzyme A hydratase, an enzyme unique to isoleucine metabolism and enoyl coenzyme A hydratase were coordinately induced, but that 3-hydroxyacyl coenzyme A dehydrogenase was under separate control. The hydratase was purified 180-fold from isoleucine cells, and its physical and catalytic properties reported. The highest activity was with crotonyl coenzyme A,Vmax = 1100 x 10(3) moles/min mole enzyme, next was tiglyl coenzyme A, Vmax = 61 x 10(3) moles/min mole enzyme, and last was 3-methyl-crotonyl coenzyme A, Vmax = 2.3 x 10(3) moles/min mole enzyme. Enzyme purified from butyrate cells had the same elution patterns during column chromatography and catalytic properties as the enzyme from isoleucine cells. These data support the conclusion that a single enzyme in P. putida is responsible for the hydration of both tiglyl coenzyme A and crotonyl coenzyme A.
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PMID:The role of enoyl-coa hydratase in the metabolism of isoleucine by Pseudomonas putida. 67 16

L-threonine deaminase from spinach is inhibited by D- and L-cysteine. The inhibition patterns by D-cysteine and by L-cysteine are non-competitive. The value of Ki for D-cysteine and L-cysteine is of the same order of magnitude. Inhibitions by L-isoleucine and L-cysteine are additional. These results indicate that inhibition by L-cysteine occurs on a site of enzyme which is different from the binding site for L-isoleucine and L-valine. Probably L-cysteine and D-cysteine form the thiazolidinic ring with a PLP mole. Which is not costituent of the active site, but located in a different region.
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PMID:Spinach threonine dehydratase. Inhibition by L-cysteine and D-cysteine. 73 Apr 95

An acidic protein, extractable in neutral salt solutions from rat skin, was markedly enriched when precipitated by dialysis against 0.5 M acetic acid. After dissolving the precipitate in 0.5 M Tris-HCl buffer, pH 8.0, the protein was disaggregated by the addition of the nonionic detergent Triton X-100 and purified by chromatography on Sephadex G-100 and DEAE-Sephadex A-50 columns. The protein isolated under nondenaturing conditions appeared to be essentially homogeneous by its migration as a single band on (a) cellulose acetate membrane electrophoresis at pH 8.6; (B) 4% and 7.5% polyacrylamide gel electrophoresis at ph 8.9; (C) sodium dodecyl sulfate (10%) polyacrylamide gel electrophoresis at pH 7.0; and by (d) its complete freedom from collagen, the major contaminating protein. The molecular weight of the protein was determined as 76,000 +/- 2,000 from its electrophoretic mobility in sodium dodecyl sulfate polyacrylamide gels and 75,000 from its elution volume in Sephadex G-100 columns. Reduction and alkylation of the protein failed to generate smaller subunits. The amino acid composition of the protein showed that it was relatively rich in glutamic and aspartic acids, which together comprised 25% of its total residues. Hydrophobic amino acids like phenylalanine, leucine, isoleucine, valine, methionine, alanine, proline, and cystine accounted for about 34% of the total residues in the protein. No free NH2-terminal amino acid could be detected in the purified protein by the dansylation method. Each mole of protein contained 11 mol of phosphate. Triton X-100 was necessary for achieving nondestructive disaggregation of the acidic protein. Each mole of protein bound about 3200 mol of Triton X-100 or 10 mol of Congo red. While the detergent binding could be reversed by dialysis, Congo red formed a stable complex with the protein.
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PMID:Purification and properties of an acidic protein from rat skin. 81 54

By repeated uv-irradiation the quantity of all free amino acids (per surface unit) in human horny layer increase considerably. 4 different groups of substances are found by taking the relative values in mole per cent. 1. No difference for urea, threonine, serine, glutamine, tyrosine and ammonia. 2. Decrease of about 20 p.c. for glutaminic acid, citrulline, arginine, histidine. 3. Increase of about 20 p.c. for urocanic acid, aspartic acid, proline, glycine, valine, isoleucine. 4. The rest of amino acids increase about 30--50 p.c.
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PMID:[Modification of relative amount of free amino acids in the stratum corneum of human epidermis by special factors of the environment. I. The influence of UV-irradiation (author's transl)]. 90 65

A new antibiotic named 61-26 active against gram-positive bacteria and some fungi was isolated from a Bacillus strain. The antibiotic is a weakly basic peptide slightly soluble in aqueous alcohols. An approximate empirical formula of C50H93N11O17 and constituent amino acids of aspartic acid (1 mole), serine(2 moles), alanine (2moles), and sum of valine and isoleucine (2 moles) are indicated.
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PMID:Isolation of a new peptide antibiotic complex 61-26. Studies on antibiotics from the geneus Bacillus. V. 111 65

Solitary mastocytoma (mast cell naevus) of the skin represents a relatively rare dermal tumour. Its occurrence on the lower eyelid is exceptional. We report the case of a 4 month old male infant who exhibited a firm, yellowish nodule (1 cm in maximum diameter) on the lower lid of the right eye from birth. Histologically, the tumour consisted of strongly metachromatic tissue mast cells (TMC) infiltrating the whole dermis, the adjacent subcutaneous tissue and the lid muscle. Since comparable skin lesions in other sites were not observed, a diagnosis of solitary mastocytoma was made. Immunocytological investigations revealed strong reactivity of the TMC to antisera against vimentin, common leucocyte antigen (CLA), alpha 1-antitrypsin (alpha 1-AT) and alpha 1-antichymotrypsin (alpha 1-ACT). A minor proportion of the TMC reacted to antisera against lysozyme and KiB3. Surprisingly, the TMC also reacted to antisera against certain regulatory peptides (RP), namely adrenocorticotropic hormone (ACTH), peptide histidine isoleucine (PHI), leu-enkephalin and met-enkephalin. However, absorption controls revealed that the immunostaining for ACTH and the two enkephalins was non-specific. The immunocytological phenotype of TMC suggests a close relationship to the myeloid-monocytic lineage, but a possible relationship between TMC and the diffuse neuroendocrine system needs further investigation.
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PMID:Solitary mastocytoma of the eyelid. A case report with special reference to the immunocytology of human tissue mast cells, and a review of the literature. 312 Apr 1

The two major apolipoproteins of marmoset serum have been isolated and characterized, and on the basis of physicochemical and immunological criteria are homologous with the human AI and B-100 proteins. Marmoset apolipoprotein AI was the principal protein of high-density lipoproteins (HDL) and was purified by gel filtration chromatography and electrophoresis in alkaline-urea polyacrylamide gel followed by electrophoretic elution. Purified marmoset apolipoprotein AI displayed an Mr of approx. 27000, was polymorphic (five forms) on isoelectric focussing, with pI values in the range 4.8-5.0, and migrated similarly to human apolipoprotein AI in alkaline-urea gels. An overall resemblance was seen in the amino acid composition of marmoset apolipoprotein AI and that of its human counterpart with the notable exception that marmoset AI contained 1 isoleucine residue/mole. An immunological reaction of partial identity between the human and monkey proteins was seen upon immunodiffusion of their HDLs against antiserum to human apolipoprotein AI. Marmoset B-100 was the predominant apoprotein of VLDL and LDL, resembling the human protein in its elution profile on gel filtration chromatography in anionic detergent, and in its high apparent Mr (approx. 520000). The marmoset and human B-100 proteins were alike in amino acid composition and carbohydrate content. Moreover, their immunological behaviour with an antiserum to marmoset apolipoprotein B showed them to share certain antigenic determinant(s). We conclude that the physicochemical properties of the principle apolipoproteins of Callithrix jacchus, a New World primate, markedly resemble those of the human AI and B-100 proteins, suggesting therefore that they may function similarly in lipid transport and metabolism. Counterparts to human apolipoproteins AII, E, CII and CIII have also been tentatively identified.
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PMID:Isolation, characterization and comparative aspects of the major serum apolipoproteins, B-100 and AI, in the common marmoset, Callithrix jacchus. 641 12

Four of the principle apolipoproteins of murine serum have been isolated and characterized. On the basis of their physicochemical properties, they are homologous with the human and rat apoA-I, A-II, B, and C-III. The group of apolipoproteins of middle to low molecular weight, i.e., A-I, A-II and C-III, were separated from the protein moiety of high density lipoproteins (HDL) by gel filtration chromatography, followed by electrophoresis in alkaline-urea polyacrylamide gel with electrophoretic elution. Murine apoA-I, the major protein of HDL (60-80%) displayed an Mr of approximately 27,000, and was polymorphic (four prominent isoproteins with isoelectric points in the range of pH 5.5-5.7). The amino acid profiles of mouse, rat, and human apoA-I generally resembled each other, the former being distinguished by a content of one isoleucine residue per mole. Amino terminal sequence analysis revealed marked homology between the mouse, rat, dog, and human proteins; mouse and rat apoA-I differed at residues 9 and 18 with potential dissimilarities at residues 5 and 15, while the murine and canine sequences were distinct at residues 6, 9, 13, 15, and 30. Apolipoprotein A-II was a monomer, exhibiting an Mr approximately 11,000 in SDS gels; in addition, it was polymorphic (three apparent isoproteins with pI in the pH range 5.05-5.2), and resembled its human and rat counterparts in amino acid composition. ApoC-III, an acidic peptide of pI 4.74 and of Mr approximately 9,600, possessed an amino acid composition very like that of the homologous human and rat proteins. The homology of mouse apoC-III with the human protein was confirmed by NH2-terminal sequence analysis, which revealed identical amino acids in six positions (1, 2, 4, 8, 9, and 13). As shown earlier (Camus et al. 1983. J. Lipid Res. 24: 1210-1228), two forms of immunologically reacting apoB predominated in mouse VLDL and LDL. After isolation of these lipoproteins in the presence of 1 mM PMSF, the apparent sizes of the high and low Mr forms, apoBH and apoBL, were in the ranges approximately 400,000-530,000 and approximately 250,000-280,000, respectively, according to the SDS gel system. We observed that inclusion of 1 mM PMSF was essential to retard degradation of the high Mr form apoBH. The murine B proteins were isolated from apoVLDL and apoLDL by gel filtration chromatography on Sephadex G150 in anionic detergent, and displayed apparent Mr values of 460,000 (apoBH) and 250,000 (apoBL) in 3% SDS gels.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The lipid transport system in the mouse, Mus musculus: isolation and characterization of apolipoproteins B, A-I, A-II, and C-III. 643 19


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