Naslov
Biocatalytic scope of halohydrin dehalogenase from Mycobacterium sp. GP1 (HheB2)

Autori
Mehić, Emina ; Findrik Blažević, Zvjezdana ; Majerić Elenkov, Maja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstracts / - Graz, 2021, 162-162

Skup
15th International Symposium on Biocatalysis and Biotransformations (Biotrans 2021)

Mjesto i datum
Online, 19.07.2021. - 22.07.2021

Vrsta sudjelovanja
Poster

Vrsta recenzije
Recenziran

Ključne riječi
biocatalysis ; halohydrin dehalogenase ; epoxide ; kinetic resolution

Sažetak
Halohydrin dehalogenases (HHDHs) belong to a distinct group of enzymes catalyzing the removal of a halide ion and a proton from a vicinal halohydrin with formation of an epoxide. Moreover, these enzymes can catalyze the epoxide ring-opening reactions with a range of anionic nucleophiles affording β-substituted alcohols as products. Based on sequence similarities, they are divided into 7 phylogenetic groups: A, B, C, D, E, F and G. Activity, enantioselectivity and enantiopreference are dependent on the type of enzyme and the substrate structure.[3] Among all, the enzyme HheC from Agrobacterium radiobacter (group C) is the most studied because of its high enantioselectivity and wide nucleophile scope. However, the major shortcoming of HheC is its narrow substrate tolerance, due to the relatively small active site. To expand the catalytic relevance of HHDHs we focus our attention to an enzyme from different organism. The HheB2 from Mycobacterium sp. GP1 (group B) has been previously characterised as non-enantioselective enzyme, and neglected as biocatalyst. In this work HheB2 was investigated in the ring-opening reaction on a set of 20 structurally different aliphatic and aromatic epoxides using sodium azide as nucleophile. The screening confirmed low to moderate enantioselectivity of HheB2 towards monosubstituted epoxides, however high activity and enantioselectivity in conversion of 2, 2-disubstituted (E-values up to >200). Similar to HheC, the large enhancement of enantioselectivity is obtained when a second substituent (methyl or ethyl) is present at the chiral centre. The results further extend the repertoire of enantioselective HHDHs and their application in the kinetic resolution of epoxides.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA