# Methods in Enzymology # Chapter Six - Computational investigations of B12-dependent enzymatic reactions Link: https://www.sciencedirect.com/science/article/abs/pii/S0076687922000027 Persistent Link using digital object identifier: https://doi.org/10.1016/bs.mie.2022.01.002 ==[Open in Readwise](https://readwise.io/reader/shared/01h945cb0fkz96adg7vce1fyb6)== ### Citation: Megan J. Toda, Arghya P. Ghosh, Saurav Parmar, Pawel M. Kozlowski, Chapter Six - Computational investigations of B12-dependent enzymatic reactions, Editor(s): E. Neil G. Marsh, Methods in Enzymology, Academic Press, Volume 669, 2022, Pages 119-150, ISSN 0076-6879, ISBN 9780323955577, https://doi.org/10.1016/bs.mie.2022.01.002. (https://www.sciencedirect.com/science/article/pii/S0076687922000027) Abstract: Nature employs two biologically active forms of vitamin B12, adenosylcobalamin (or coenzyme B12) and methylcobalamin, as cofactors in molecular transformations both in bacteria and mammals. Computational chemistry, guided by experimental data, has been used to explore fundamental characteristics of these enzymatic reactions. In particular, the quantum mechanics/molecular mechanics (QM/MM) method has proven to be a powerful tool in elucidating important characteristics of B12-dependent enzymatic reactions. Herein, we will present a brief tutorial in conducting QM/MM calculations for B12 enzymatic reactions. We will summarize recent contributions that target the use of QM/MM calculations in both photochemical and enzymatic reactions including AdoCbl-dependent ethanolamine ammonia lyase, glutamate mutase, and photoreceptor CarH. Keywords: QM/MM; Computational chemistry; Cobalamin; CoC bond; Methylcobalamin; Coenzyme B12; Enzymatic catalysis