6232-19-5Relevant articles and documents
Repurposing Nonheme Iron Hydroxylases to Enable Catalytic Nitrile Installation through an Azido Group Assistance
Davidson, Madison,McNamee, Meredith,Fan, Ruixi,Guo, Yisong,Chang, Wei-Chen
supporting information, p. 3419 - 3423 (2019/03/07)
Three mononuclear nonheme iron and 2-oxoglutarate dependent enzymes, l-Ile 4-hydroxylase, l-Leu 5-hydroxylase and polyoxin dihydroxylase, are previously reported to catalyze the hydroxylation of l-isoleucine, l-leucine, and l-α-amino-δ-carbamoylhydroxyvaleric acid (ACV). In this study, we showed that these enzymes can accommodate leucine isomers and catalyze regiospecific hydroxylation. On the basis of these results, as a proof-of-concept, we demonstrated that the outcome of the reaction can be redirected by installation of an assisting group within the substrate. Specifically, instead of canonical hydroxylation, these enzymes can catalyze non-native nitrile group installation when an azido group is introduced. The reaction is likely to proceed through C - H bond activation by an Fe(IV)-oxo species, followed by azido-directed C-N bond formation. These results offer a unique opportunity to investigate and expand the reaction repertoire of Fe/2OG enzymes.
Syntheses of optically pure α-amino acids from 3-amino-2-oxetanone salts
-
, (2008/06/13)
A process for the preparation of optically pure α-amino acids comprising the nucleophilic ring-opening of 3-amino-2-oxetanone salts. N-Protected serine β-lactones are deprotected to form heretofore unknown 3-amino-2-oxetanone and its corresponding salts. In turn these previously unknown 3-amino-2-oxetanone salts may be used in the synthesis of other novel or rare stereochemically-pure free amino acids.
PURIFICATION AND PROPERTIES OF β-CYANO-L-ALANINE SYNTHASE FROM SPINACIA OLERACEA
Ikegami, Fumio,Takayama, Kyoko,Tajima, Chiho,Murakoshi, Isamu
, p. 2011 - 2016 (2007/10/02)
β-Cyano-L-alanine synthase was purified ca 6200-fold to homogeneity from the leaves of spinach (Spinacia oleracea).The purified enzyme has an apparent Mr of 60 000 and can be dissociated into identical subunits of Mr 30 000.The subunits each contain one molecule of pyridoxal 5'-phosphate.The Km value is 2.3 mM for L-cysteine and 0.73 mM for cyanide. β-Cyano-L-alanine synthase from S. oleracea also catalyses the formation of some S-substituted L-cysteines and some heterocyclic β-substituted alanines from L-cysteine or O-acetyl-L-serine.The specificity of these additional catalytic activities of the purified enzyme are compared with those of cysteine synthase purified from the same plant, and with those of β-cyano-L-alanine synthase purified from other sources.Some other properties, including the amino acid composition of the purified enzyme, are also described. - Key Word Index: Spinacia oleracea; Chenopodiaceae; spinach; β-cyano-L-alanine synthase; cysteine synthase; enzyme purification; amino acid composition; L-cysteine; O-acetyl-L-serine; β-cyano-L-alanine; heterocyclic β-substituted alanines.