Wetmore, Stacey D. Smith, David M. Golding, Bernard T. Radom, Leo Interconversion of (<i>S</i>)-Glutamate and (2<i>S</i>,3<i>S</i>)-3-Methylaspartate:  A Distinctive B<sub>12</sub>-Dependent Carbon-Skeleton Rearrangement The interconversion of (<i>S</i>)-glutamate and (2<i>S</i>,3<i>S</i>)-3-methylaspartate catalyzed by B<sub>12</sub>-dependent glutamate mutase is discussed using results from high-level ab initio molecular orbital calculations. Evidence is presented regarding the possible role of coenzyme-B<sub>12</sub> in substrate activation and product formation via radical generation. Calculated electron paramagnetic resonance parameters support experimental evidence for the involvement of substrate-derived radicals and will hopefully aid the future detection of other important radical intermediates. The height of the rearrangement barrier for a fragmentation−recombination pathway, calculated with a model that includes neutral amino and carboxylic acid substituents in the migrating glycyl group, supports recent experimental evidence for the interconversion of (<i>S</i>)-glutamate and (2<i>S</i>,3<i>S</i>)-3-methylaspartate through such a pathway. Our calculations suggest that the enzyme may facilitate the rearrangement of (<i>S</i>)-glutamate through (partial) proton-transfer processes that control the protonation state of substituents in the migrating group. Distinctive B 12;calculation;future detection;evidence;pathway;glutamate mutase;rearrangement barrier;resonance parameters support;methylaspartate;product formation;ab initio;carboxylic acid substituents;glycyl group;interconversion;protonation state;substrate activation;B 12 2001-07-27
    https://acs.figshare.com/articles/journal_contribution/Interconversion_of_i_S_i_-Glutamate_and_2_i_S_i_3_i_S_i_-3-Methylaspartate_A_Distinctive_B_sub_12_sub_-Dependent_Carbon-Skeleton_Rearrangement/3632640
10.1021/ja004246f.s001