EC Number   |
General Information |
Reference |
|---|
   3.3.2.8 | malfunction |
replacement of th catalytic aspartic acid residue to alanine (D82A) completely abolishes activity towards the tested substrates cyclohexene epoxide and (+)-limonene epoxide |
753544 |
| 3.3.2.8 | malfunction |
replacement of the catalytic aspartic acid residue to alanine (D80A) completely abolishes activity towards the tested substrates cyclohexene epoxide and (+)-limonene epoxide |
753544 |
| 3.3.2.8 | more |
quantum mechanics/molecular mechanics (QM/MM) free energy calculations for the reaction with molecular dynamics simulations of the enzyme internal dynamics, and the calculation of binding affinities (using the WaterSwap method) for various representatives of the enzyme conformational ensemble, show that the presence of natural or non-natural substrates differentially modulates the dynamic and catalytic behavior of LEH. The cross-talk between the protein and the ligands favors the selection of specific substrate-dependent interactions in the binding site, priming reactive complexes to select different preferential reaction pathways. LEH substrate binding pocket structure, LEH forms a stable homodimer, and each monomer can bind a substrate molecule within its catalytic pocket, overview. Crucial role of monomer-monomer interactions in stabilizing and tuning LEH dynamics and stability. Hydrolysis by LEH occurs via a complex mechanism, the Asp101-Arg99-Asp132 triad drives a concerted reaction involving the deprotonation of a water molecule by Asp132, the nucleophilic attack of the resulting hydroxide ion on the epoxide and protonation of the oxirane ring by the protonated Asp101 (specifically labeled Ash101). Arg99 is strongly associated through hydrogen bonds and electrostatic interactions with both Asp101 and Asp132 and even if it is not directly involved in the reaction mechanism, its mutation results in a deactivated enzyme. This complex picture is completed by the proper positioning and activation of the nucleophilic water by the H-bond network formed by Asn55 and Tyr53 (and Asp132 itself). In the model, the side chains of the residues of the catalytic triad, the water molecule and the epoxide are included in the QM region. The opening of the epoxide can result from the attack on either of the two carbon atoms of the LEO oxirane ring. Experimental evidence indicates that the water molecule privileges the attack on the more substituted C1 atom |
-, 752350 |
| 3.3.2.8 | more |
reaction quantum mechanics/molecular mechanics (QM/MM) calculations, molecular dynamics simulations and active site structures of wild-type and mutant enzymes, overview. Rhodococcus erythropolis DCL14 LEH has the exceptionally low molecular mass of 16 kDa, which is too small to contain any of the highly conserved motifs of the catalytic triad used by alpha/beta-hydrolase folded EHs. LEH has a narrow substrate range compared to other EHs |
-, 752797 |
| 3.3.2.8 | more |
structural and computational insight into the catalytic mechanism of limonene epoxide hydrolase variants in stereoselective transformations, molecular dynamics simulations |
753976 |
| 3.3.2.8 | more |
the enzyme's catalytic mechanism is different from that of the epoxide hydrolases, EHs, belonging to the alpha/beta-hydrolase superfamily. The LEH enzyme active site contains three residues (Asp101, Arg99, and Asp132) that act in a concerted fashion to activate a water molecule which is able to open the epoxide ring without the formation of a covalently bound alkyl-enzyme intermediate. Importance of the catalytic Asp80 residues for the enzymatic activity of Tomsk-LEH. The LEH substrate binding pocket appears to have high affinity for polar molecules and additional electron density is observed in the active site pocket in the different LEH structure. Active site structure, overview |
753544 |
| 3.3.2.8 | more |
the enzyme's catalytic mechanism is different from that of the epoxide hydrolases, EHs, belonging to the alpha/beta-hydrolase superfamily. The LEH enzyme active site contains three residues (Asp101, Arg99, and Asp132) that act in a concerted fashion to activate a water molecule which is able to open the epoxide ring without the formation of a covalently bound alkyl-enzyme intermediate. Importance of the catalytic Asp82 residues for the enzymatic activity of CH55-LEH. The LEH substrate binding pocket appears to have high affinity for polar molecules and additional electron density is observed in the active site pocket in the different LEH structure. Active site structure, overview |
753544 |
| 3.3.2.8 | more |
the N-terminal extension of Re-LEH involved in the intersubunit interface which increases the buried surface area. The LEH monomer fold contains a curved six-stranded mixed beta-sheet, with three alpha-helices packed onto its concave side to form the active site pocket. Active site structure, overview |
753544 |
| 3.3.2.8 | physiological function |
epoxide hydrolases (EHs) catalyze the hydrolysis of epoxides to vicinal diols. EHs are found in all types of living organisms, including mammals, invertebrates, plants, bacteria and fungi. They have three main functions: detoxification, metabolism, and synthesis of signaling molecules |
-, 752797 |
| 3.3.2.8 | physiological function |
limonene-1,2-epoxide hydrolases (LEHs), a subset of the epoxide hydrolase family, present interesting opportunities for the mild, regio- and stereo- selective hydrolysis of epoxide substrates. LEHs show moderate enantioselectivity for non-natural ligands, combined with narrow substrate specificity |
-, 752350 |
