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The fate of certain organic acids and amides in the rabbit; further observations on the hydrolysis of amides by tissue extracts. Biochem J 2004; 47:294-9. [PMID: 14800883 PMCID: PMC1275209 DOI: 10.1042/bj0470294] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Cytotoxic agents: 1, methylol amides with tumour inhibitory activity, and related inactive compounds. BRITISH JOURNAL OF PHARMACOLOGY AND CHEMOTHERAPY 2004; 6:201-34. [PMID: 14848452 PMCID: PMC1509224 DOI: 10.1111/j.1476-5381.1951.tb00635.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
Ammonium lactate and a variety of amides and amino acids were infused into one renal artery of anesthetized dogs in acidosis. Urine was collected separately from the two kidneys and rates of excretion of ammonia on the two sides were compared. The infusion of ammonium lactate resulted in a prompt increase in ammonia excretion restricted to the side infused. As much as 50% of the infused ammonia appeared as excess ammonia in the urine. The infusion of glutamine, asparagine, alanine, glycine, leucine, and glutamic acid induced bilateral increases in rates of ammonia excretion, commonly greater on the side infused. However, ammonia excretion increased significantly on the side contralateral to that infused. A much smaller fraction of the infused nitrogen appeared as urinary ammonia than when ammonium lactate was infused. The infusion of valine induced no increase in ammonia excretion by either kidney; rather, ammonia excretion was reduced. The significance of these results in relation to the study of renal metabolism of N15 compounds is discussed.
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Abstract
The direct proportionality between renal oxygen consumption and sodium reabsorption suggests a linkage between cation transport and the electron transport system (ETS). We have studied the effects of in vitro inhibitors of the ETS on sodium reabsorption in the dog kidney. Compounds known to block O2 consumption or reduce tissue levels of adenosine triphosphate (ATP) were infused in millimolar quantities into a renal artery of anesthetized dogs. We observed a unilateral diuresis following the administration of cyanide, antimycin-A and iodoacetamide; no diuresis was observed following administration of 2,4-dinitrophenol, azide, and phlorizin. These latter agents block the synthesis or facilitate the degradation of ATP. Negative results were also observed with phthiocol (a naphthoquinone), malonate, and Amytal, inhibitors of specific substrates of ETS. We interpret our results as follows. Inhibition of sodium reabsorption by cyanide and antimycin-A supports the hypothesis that renal cation transport is dependent in part upon oxidative metabolism. The failure of phlorizin and 2,4-dinitrophenol to affect sodium reabsorption suggests that cation transport may be independent of ATP synthesis or concentration in renal tissues.
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Enzymatic formation of fatty acid amides of ethanolamine by rat liver microsomes. Biochem Biophys Res Commun 1998; 10:165-70. [PMID: 14022413 DOI: 10.1016/0006-291x(63)90044-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
Four dipeptides and a tripeptide were formed when an aqueous solution of glycine and leucine was exposed to ultraviolet light in the presence of cyanamide.
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INTRANUCLEAR CHANGES IN RAT LIVER DURING THE EARLY STAGES OF FEEDING THE HEPATOCARCINOGENS THIO-ACETAMIDE AND 4-DIMETHYLAMINOAZBENZENE. Br J Cancer 1996; 19:72-82. [PMID: 14284385 PMCID: PMC2071424 DOI: 10.1038/bjc.1965.7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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THE ENZYMATIC HYDROLYSIS OF AMINO ACID BETA-NAPHTHYL AMIDES: I. PREPARATION OF AMINO ACID AND DIPEPTIDE BETA-NAPHTHYLAMIDES. J Histochem Cytochem 1996; 13:57-64. [PMID: 14284808 DOI: 10.1177/13.1.57] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The acid salts of amino acid β-naphthylamides have been found to have greater stability and solubility than their corresponding free bases. For the purpose of applying these substrates in subsequent studies in histochemical and biochemical systems, the syntheses and characteristics of a large variety of previously unreported intermediates, acid salts and free bases of amino acid β-naphthylamides and their analogues are described.
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Abstract
Acetone induces a reversible relaxation of glycerinated muscle fibers (1). We found that formamide is equally effective. Since the dielectric constant of formamide is larger and that of acetone is smaller than that of water, the change in the dielectric constant of the fiber medium after adding organic solvents has little to do with the mechanism of this organic solvent-induced relaxation. That ITP can substitute for ATP in this relaxation suggests that organic solvents, when they induce a relaxation, act on the contractile protein rather than on ATP. Comparing the relaxing effect of 11 different organic solvents, the authors propose a working hypothesis based on the assumption of a specific interaction between organic solvents and the contractile protein. Formamide induces a "clearing" response of myosin B suspensions which is an in vitro model of muscle relaxation. Effects of Mg, Ca, and ionic strength (KCl) on this clearing response are studied in comparison with the effects of these on EDTA-induced relaxation. It is then shown that the formamide-induced clearing response is less specific than the EDTA-induced clearing response with regard to the requirements for ATP and Mg.
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INTERACTION OF AROMATIC COMPOUNDS WITH ALPHA-CHYMOTRYPSIN. II. COMBINATION OF THE ISOMERIC INDOLE CARBOX AMIDES AND CARBOXYLATE IONS WITH THE ACTIVE SITE. Biochemistry 1996; 4:99-104. [PMID: 14285251 DOI: 10.1021/bi00877a017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
1. The presence of palmitoyl-CoA-l-glycerol 1-phosphate palmitoyltransferase (EC2.3.1.15) has been demonstrated in a particulate fraction of baker's yeast. 2. The enzyme has been characterized, and its activity studied as a function of pH and concentration of substrates. 3. Inhibition by thiol poisons and protection by acyl-CoA have been used to obtain information on the active site. 4. By various methods of supplying acyl radicals, the species ;palmitoyl-CoA' has been shown to be the true acyl donor to the transferase.
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PREPARATIVE METHODS FOR DISK ELECTROPHORESIS WITH SPECIAL REFERENCE TO THE ISOLATION OF PITUITARY HORMONES. Anal Biochem 1996; 6:303-15. [PMID: 14082693 DOI: 10.1016/0003-2697(63)90154-4] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
1. The reaction of alpha-chymotrypsin with sodium periodate at pH5.0 has been investigated. The enzyme consumes 2 moles of periodate/mole, and there is a concomitant fall in enzymic activity (with respect to l-tyrosine ethyl ester) to 55% of that of the native enzyme. After 3hr. no further change is observed in periodate uptake or in catalytic activity. 2. The oxidized enzyme is a homogeneous preparation of partially active chymotrypsin. 3. In the oxidized enzyme, one of the two methionine residues in the molecule has been converted into its sulphoxide. It is this reaction only that is responsible for the loss of activity. 4. The rate constants for the enzyme-catalysed acylation and deacylation reactions are unaltered by oxidation of the enzyme, both for a non-specific substrate (p-nitrophenyl acetate), and for three specific substrates: N-acetyl-l-tryptophan ethyl ester, N-acetyl-l-tryptophanamide and N-acetyl-l-valine ethyl ester. 5. The K(m) values for the aromatic substrates with the oxidized enzyme are twice those with the native enzyme. No change in Michaelis constant is seen for the non-aromatic substrate N-acetyl-l-valine ethyl ester. 6. The evidence points to the oxidized methionine residue in the modified enzyme being situated in the locus of the active site at which aromatic (or bulky) side chains of the substrates are bound.
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Abstract
O-Succinylhomoserine and N-succinylhomoserine have been synthesized. The first is rapidly transformed into the second by alkali. In acid, the second undergoes ring closure to the lactone, rather than the reverse acyl transfer. Neither supports the growth of methionine auxotrophs of Neurospora or Salmonella. However, bacterial extracts rapidly catalyze formation of a compound, chromatographically identical with cystathionine, from cysteine and O-succinylhomoserine. In the absence of cysteine the O-succinylhomoserine is converted to alpha-ketobutyrate. Both these reactions are absent from the same Salmonella mutant, and therefore are probably catalyzed by a single enzyme which is needed for methionine synthesis. Both reactions require pyridoxal phosphate. N-succinylhomoserine does not undergo either reaction.
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STUDIES ON THE HISTOCHEMICAL "LEUCINE AMINOPEPTIDASE" REACTION. 3. ON THE DIFFERENT LNA-SPLITTING ENZYMES FROM SPLEEN. Histochem Cell Biol 1996; 78:484-6. [PMID: 14188683 DOI: 10.1007/bf00736629] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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SECONDARY STRUCTURES OF NUCLEIC ACIDS IN ORGANIC SOLVENTS. IV. EFFECTS OF ELECTROLYTES. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 76:54-67. [PMID: 14068561 DOI: 10.1016/0006-3002(63)90007-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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THE ROLE OF THE NUCLEOLUS. I. TRITIATED CYTIDINE ACTIVITY IN LIVER PARENCHYMAL CELLS OF THIOACETAMIDE-TREATED RATS. ACTA ACUST UNITED AC 1996; 23:39-51. [PMID: 14228517 PMCID: PMC2106508 DOI: 10.1083/jcb.23.1.39] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Male rats of the Sherman strain were fed for 2 weeks a diet of ground purina rat chow containing 0.04 per cent thioacetamide. Animals were injected intraperitoneally with tritiated cytidine, 200µc/100 gm body weight, and sacrificed in pairs, a control and a thioacetamide-treated rat, at prescribed intervals. Liver tissues were preserved with the freeze-substitution method and postfixed in anhydrous OsO4. Other samples were fixed directly with an acetic acid-ethanol mixture (1:3). AR-10 stripping film was applied to 2- and 4-µ sections and exposed for appropriate lengths of time. Nuclear and nucleolar volumes were obtained by direct measurement. Cytoplasmic volumes were obtained with the aid of Chalkley ratios. Nucleolar and cytoplasmic RNA concentrations were calculated from cytophotometric extinction (E540 mµ) measurements. Data were expressed as grains/unit area, grains/unit area/concentration (or specific activity) and grains/total structure. In the liver parenchymal cells of thioacetamide-treated rats, the nucleolus shows vast increases in volume, RNA content, and grain count/total structure, 14-fold, 25-fold, and over 30-fold, respectively. The nucleus increases 2-fold in volume and about 3-fold in total grain count. Cytoplasmic volume increases only 20 per cent and displays a total grain count about equal to that in the control. The time course of incorporation curves for nucleolus and non-nucleolar nucleus (NNN) contain 2 distinct turnover fractions, rapid and slow. Both fractions were increased after thioacetamide treatment but remained proportional to those of controls. The unique stimulated RNA turnover in the nucleus and nucleolus, coupled to a "normal" turnover in the cytoplasm, suggests that this nuclear-nucleolar loss of label does not represent an exclusive passage of formed nuclear RNA to the cytoplasm.
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TRANSPORT OF NEUTRAL AND DIBASIC AMINO ACIDS BY HUMAN LEUKOCYTES: ABSENCE OF DEFECT IN CYSTINURIA. J Clin Invest 1996; 44:1382-93. [PMID: 14322042 PMCID: PMC292615 DOI: 10.1172/jci105243] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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ISOLATION OF 2-PHENYLACETAMIDE, INDOLE-3-ACETAMIDE, AND INDOLE-3-CARBOXALDEHYDE FROM ETIOLATED SEEDLING OF PHASEOLUS. Chem Pharm Bull (Tokyo) 1996; 11:1217-8. [PMID: 14068752 DOI: 10.1248/cpb.11.1217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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[ROLE OF THE AMIDE GROUP IN CREATINE PHOSPHOKINASE ACTIVITY]. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 73:574-81. [PMID: 14074132 DOI: 10.1016/0006-3002(63)90328-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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BIOCHEMISTRY OF ORGAN GLYCOLIPIDS. III. THE STRUCTURES OF HUMAN KIDNEY CEREBROSIDE SULFURIC ESTER, CERAMIDE DIHEXOSIDE AND CERAMIDE TRIHEXOSIDE. J Biochem 1996; 55:365-70. [PMID: 14170087 DOI: 10.1093/oxfordjournals.jbchem.a127896] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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PHARMACOLOGICAL ACTIONS AND TOXICITY OF DIMETHYL SULPHOXIDE AND OTHER COMPOUNDS WHICH PROTECT SMOOTH MUSCLE DURING FREEZING AND THAWING. ACTA ACUST UNITED AC 1996; 16:472-83. [PMID: 14207090 DOI: 10.1111/j.2042-7158.1964.tb07496.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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BACTERIAL DEGRADATION OF RIBOFLAVIN. V. STOICHIOMETRY OF RIBOFLAVIN DEGRADATION TO OXAMIDE AND OTHER PRODUCTS, OXIDATION OF C14-LABELED INTERMEDIATES AND ISOLATION OF THE PSEUDOMONAD EFFECTING THESE TRANSFORMATIONS. Arch Biochem Biophys 1996; 108:323-33. [PMID: 14240585 DOI: 10.1016/0003-9861(64)90393-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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CHARACTERIZATION OF ENZYMES HYDROLYZING ACYL NAPHTHYL AMIDES. I. MONO-AND DIHALOGEN DERIVATIVES. J Histochem Cytochem 1996; 12:674-86. [PMID: 14223934 DOI: 10.1177/12.9.674] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Abstract
The renal tubules of the shark actively reabsorb urea. They also can reabsorb acetamide and methylurea, but there is no evidence for active reabsorption of thiourea. The specificity of the transport system thus appears to be different from the urea secretory system in the frog in which thiourea is secreted but acetamide and methylurea are not secreted.
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