57230-45-2Relevant academic research and scientific papers
Kinetic and solvent isotope effects on biotransformation of aromatic amino acids and their derivatives
Kańska, Marianna,Jemielity, Jacek,Paj?k, Ma?gorzata,Pa?ka, Katarzyna,Podsadni, Katarzyna,Winnicka, El?bieta
, p. 627 - 634 (2016/12/26)
Aromatic amino acids such as l-phenylalanine, l-tryptophan, 3′,4′-dihydroxy-l-phenylalanine (l-DOPA), and their derivatives 3′,4′-dihydroxyphenylacelaldehyde (DOPAL) and 3′,4′-dihydroxyphenylethanol (DOPET), play an essential role in human metabolic processes. Incorrect or slow biotransformation of these compounds leads to some metabolic dysfunctions and in some cases to some neurodegenerative diseases. Therefore, studies of the biotransformation mechanisms of these metabolites draw biochemists' and medical researchers' attention. This study investigates the mechanisms of biotransformation of the aforementioned compounds using kinetic (KIE) and solvent (SIE) isotope effect methods. The overview presents the results and the numerical values of KIE and SIE methods, obtained in the study of biotransformation of l-phenylalanine, 5′-chloro-l-tryptophan, and l-DOPA, catalyzed by the enzymes from the lyases group (phenylalanine ammonia lyase, tryptophan indole-lyase, and tyrosine decarboxylase). Deuterium KIE was also determined during the deamination of 2′-chloro-l-phenylalanine in the presence of the enzyme l-phenylalanine dehydrogenase, as well as in the conversion of DOPAL into DOPET catalyzed by the enzyme alcohol dehydrogenase. The values of KIE and SIE have been determined using a noncompetitive spectrophotometric and a competitive (combined with internal radioactivity standard) radiometric methods.
Synthesis of tritium labeled isotopomers of L-tyrosine
Augustyniak,Suchecki,Jemielity,Kanski,Kanska
, p. 559 - 567 (2007/10/03)
The synthesis of four selectively labeled isotopomers of L-tyrosine, (L-Tyr), using chemical and enzymatic methods is reported. Four tritium labeled isotopomers of L-phenylalanine (L-Phe) - [2-3H]-, [2′,6′-3H2]-, [3R-3H]- and [3S-3H]- have been synthesized using a combination of chemical and enzymatic methods. The labeled isotopomers of L-Phe have been converted into [2-3H]-, [2′,6′-3H2]-, [3R-3H]-, and [3S-3H]-L-Tyr by using the enzyme L-phenyl-alanine 4′-monooxygenase. Copyright
Synthesis of tritium labeled [3R-3H]-, and [3S-3H]-L-phenylalanine
Jemielity,Kanski,Kanska
, p. 295 - 304 (2007/10/03)
The synthesis of two selectively labeled isotopomers of L-phenylalanine, (Phe), using chemical and enzymatic methods is reported. The [3R-3H]-L-Phe isotopomer has been obtained from [3-3H]cinnamic acid prepared from benzaldehyde and malonic acid using tritiated water as a source of radioactive label, and by addition of ammonia in the presence of enzyme PAL. The [3S-3H]-L-Phe isotopomer has been synthesized by addition of ammonia to cinnamic acid in a buffered medium containing PAL and tritiated water.
Steric Course of the Reactions Catalyzed by 5-Enolpyruvylshikimate-3-phosphate Synthase, Chorismate Mutase, and Anthranilate Synthase
Asano, Y.,Lee, J. J.,Shieh, T. L.,Spreafico, F.,Kowal, C.,Floss, H. G.
, p. 4314 - 4320 (2007/10/02)
To probe the steric course of several reactions in the shikimate pathway, (1R,2R)-glycerol was synthesized and fed to cultures of Klebsiella pneumoniae mutant 62-1.The accumulated chorismic acid, labeled from endogenously formed (E)-phosphoenolpyruvate, was isolated and degraded by hydrogenation of the side-chain double bond and cleavage of the ether linkage to D,L-lactic-acid.Resolution of the latter and determination of the methyl group configuration in the two enantiomers demonstrated predominant E configuration of the chorismic acid.It follows that the addition and the elimination step in the 5-enolpyruvylshikimate-3-phosphate (ESP) synthase reaction proceed with opposite stereochemistry, i.e., anti/syn or syn/anti.Incubation of the above chorismic acid with anthranilate synthase produced pyruvate of predominantly S configuration, indicating stereospecific protonation on the re face of the side chain.Conversion of the (E)-chorismic acid into phenylalanine and tyrosine with whole cells of E. coli and configurational analysis of these amino acids by conversion into pyruvate carrying a chiral methyl group with phenylalanine hydroxylase and/or tyrosine phenol-lyase indicated that the chorismate mutase reaction proceeds via a chair transition state.
