Open AccessA quantum chemical study of the enzymatic deamination of benzoadenine derivatives
Author(s) -
OROZCO Modesto,
CANELA Enric I.,
FRANCO Rafael
Publication year - 1990
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1990.tb15383.x
Subject(s) - deamination , active site , chemistry , adenosine deaminase , hydrogen bond , ab initio , adenosine , protonation , ribose , context (archaeology) , computational chemistry , stereochemistry , enzyme , organic chemistry , molecule , biochemistry , biology , ion , paleontology
A theoretical study is presented, where, by using both ab initio and semi‐empirical methodologies, the properties of benzoadenine derivatives as substrates of adenosine deaminase are discussed. The results suggest that lin‐benzoadenine and lin‐benzoadenosine can be recognized with an affinity similar to that of adenosine, but only if they are introduced about 0.12 nm deeper inside the active site of the enzyme than the natural substrate adenosine. This fact implies the existence of non‐linear hydrogen bonds inside the active site of adenosine deaminase. Ab initio molecular electrostatic potential values suggest that these hydrogen bonds can exist, and have stability similar to that of linear hydrogen bonds. Finally, the great rate of deamination of lin‐benzoadennie, comparable with that of adenosine despite the absence of the ribose, is explained in the context of the hypothesis that the protonation at the N1 atom is the rate‐determining step of the whole deamination reaction.