Catalytic mechanism of limonene epoxide hydrolase: a theoretical study
2005 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 127, no 41, 14339-14347 p.Article in journal (Refereed) Published
The catalytic mechanism of limonene epoxide hydrolase (LEH) was investigated theoretically using the density functional theory method B3LYP. LEH is part of a novel limonene degradation pathway found in Rhodococcus erythropolis DCL14, where it catalyzes the hydrolysis of limonene-1,2-epoxide to give limonene-1,2-diol. The recent crystal structure of LEH was used to build a model of the LEH active site composed of five amino acids and a crystallographically observed water molecule. With this model, hydrolysis of different substrates was investigated. It is concluded that LEH employs a concerted general acid/general base-catalyzed reaction mechanism involving protonation of the substrate by Asp101, nucleophilic attack by water on the epoxide, and abstraction of a proton from water by Asp132. Furthermore, we provide an explanation for the experimentally observed regioselective hydrolysis of the four stereoisomers of limonene-1,2-epoxide.
Place, publisher, year, edition, pages
2005. Vol. 127, no 41, 14339-14347 p.
Amino acids; Catalysis; Degradation; Hydrolysis; Mathematical models; Probability density function; Limonene degradation; Limonene epoxide hydrolase (LEH); Regioselective hydrolysis; Rhodococcus erythropolis DCL14
IdentifiersURN: urn:nbn:se:kth:diva-7168DOI: 10.1021/ja050940pISI: 000232605600057ScopusID: 2-s2.0-26844530203OAI: oai:DiVA.org:kth-7168DiVA: diva2:12095
QC 201008112007-05-222007-05-222010-08-11Bibliographically approved