15142-91-3Relevant articles and documents
Stepwise O-Atom Transfer in Heme-Based Tryptophan Dioxygenase: Role of Substrate Ammonium in Epoxide Ring Opening
Shin, Inchul,Ambler, Brett R.,Wherritt, Daniel,Griffith, Wendell P.,Maldonado, Amanda C.,Altman, Ryan A.,Liu, Aimin
, p. 4372 - 4379 (2018)
Heme-based tryptophan dioxygenases are established immunosuppressive metalloproteins with significant biomedical interest. Here, we synthesized two mechanistic probes to specifically test if the α-amino group of the substrate directly participates in a critical step of the O atom transfer during catalysis in human tryptophan 2,3-dioxygenase (TDO). Substitution of the nitrogen atom of the substrate to a carbon (probe 1) or oxygen (probe 2) slowed the catalytic step following the first O atom transfer such that transferring the second O atom becomes less likely to occur, although the dioxygenated products were observed with both probes. A monooxygenated product was also produced from probe 2 in a significant quantity. Analysis of this new product by HPLC coupled UV-vis spectroscopy, high-resolution mass spectrometry, 1H NMR, 13C NMR, HSQC, HMBC, and infrared (IR) spectroscopies concluded that this monooxygenated product is a furoindoline compound derived from an unstable epoxyindole intermediate. These results prove that small molecules can manipulate the stepwise O atom transfer reaction of TDO and provide a showcase for a tunable mechanism by synthetic compounds. The product analysis results corroborate the presence of a substrate-based epoxyindole intermediate during catalysis and provide the first substantial experimental evidence for the involvement of the substrate α-amino group in the epoxide ring-opening step during catalysis. This combined synthetic, biochemical, and biophysical study establishes the catalytic role of the α-amino group of the substrate during the O atom transfer reactions and thus represents a substantial advance to the mechanistic comprehension of the heme-based tryptophan dioxygenases.
Structure of side-chain-3-substituted indoles and color intensity in reaction with glyoxylic acid-sulfuric acid
Brieksorn,Mechtold
, p. 950 - 955 (1972)
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Enantioselective Enzymatic Reduction of Acrylic Acids
An, Chihui,Shaw, Megan H.,Tharp, Annika,Verma, Deeptak,Li, Hongming,Wang, Heather,Wang, Xiao
supporting information, p. 8320 - 8325 (2020/11/03)
An ene-reductase (ERED 36) with broad substrate specificity was identified, and optimization studies led to the development of an enzymatic protocol for the reduction of α,β-unsaturated acids under mild, aqueous conditions. The substrate scope includes aromatic- A nd aliphatic-substituted acrylic acids, as well as cyclic α,β-substituted acrylic acids, yielding chiral α-substituted acids with exquisite levels of enantioselectivity (>99% ee).
Mechanistic Insights into the Radical S-adenosyl- l -methionine Enzyme NosL from a Substrate Analogue and the Shunt Products
Ji, Xinjian,Li, Yongzhen,Jia, Youli,Ding, Wei,Zhang, Qi
, p. 3334 - 3337 (2016/03/22)
The radical S-adenosyl-l-methionine (SAM) enzyme NosL catalyzes the transformation of l-tryptophan into 3-methyl-2-indolic acid (MIA), which is a key intermediate in the biosynthesis of a clinically interesting antibiotic nosiheptide. NosL catalysis was i
