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Nature's Sniper for Long‐Range Specific Protein Oxidation
Author(s) -
Liu Aimin
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.573.2
Subject(s) - chemistry , redox , cofactor , electron transfer , catalysis , combinatorial chemistry , enzyme , photochemistry , biochemistry , organic chemistry
In recent years, it has come to light that radical generation and long‐range electron transfer as a means to transport oxidizing equivalents is increasingly regarded as an effective strategy for biological systems to perform demanding redox reactions in a controlled manner. One such example is the biosynthesis of tryptophan tryptophylquinone (TTQ), the catalytic center of methylamine dehydrogenase. TTQ is formed through posttranslational modification catalyzed by MauG, an enzyme which employs old cofactors, namely c‐type hemes, to catalyze the oxidation of two tryptophan residues of a precursor protein, preMADH. The MauG‐catalyzed reaction is a three‐step, six‐electron oxidation process. Each step requires one equivalent of H 2 O 2 as the oxidant.We have previously shown that an unprecedented high‐valence bis‐Fe(IV) intermediate of MauG orchestrates the oxidative production of TTQ. 1 ,2 From our most recent EPR study, a novel Trp‐based di‐radical intermediate has been captured in the substrate protein preMADH as a result of oxidation by the bis‐Fe(IV) species. 3 In this presentation, I will focus on the discoveries of a novel, long‐range, remote enzyme catalysis mechanism of TTQ biosynthesis Acknowledgement This work is supported by NIH grant NIH R01GM108988, NSF grant MCB‐0843537, and GRA Distinguished Scholar Program.