Naslov
Impact of organic solvents on the catalytic performance of halohydrin dehalogenase

Autori
Milčić, Nevena ; Švaco, Petra ; Sudar, Martina ; Tang, Lixia ; Findrik Blažević, Zvjezdana ; Majerić Elenkov, Maja

Izvornik
Applied microbiology and biotechnology (0175-7598) 107 (2023), 7-8; 2351-2361

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
halohydrin dehalogenases ; biocatalysis ; organic solvents ; activity ; stability ; enantioselectivity

Sažetak
Biocatalytic transformations in organic synthesis often require the use of organic solvents to improve substrate solubility and promote the product formation. Halohydrin dehalogenases (HHDHs) are enzymes that catalyze the formation and conversion of epoxides, important synthetic class of compounds that are often sparingly soluble in water and prone to hydrolysis. In this study, the activity, stability, and enantioselectivity of HHDH from Agrobacterium radiobacter AD1 (HheC) in form of cell-free extract were evaluated in various aqueous-organic media. A correlation was discovered between the enzyme activity in the ring-closure reaction and logP of the solvent. Knowledge of such a relationship makes biocatalysis with organic solvents more predictable, which may reduce the need to experiment with a variety of solvents in the future. The results revealed a high enzyme compatibility with hydrophobic solvents (e.g., n-heptane) in terms of activity and stability. Regarding the HHDH applicability in an organic medium, inhibitions by a number of solvents (e.g., THF, toluene, chloroform) proved to be a more challenging problem than the protein stability, especially in the ring-opening reaction, thus suggesting which solvents should be avoided. In addition, solvent tolerance of the thermostable variant ISM-4 was also evaluated, revealing increased stability and to a lesser extent enantioselectivity compared to the wild-type. This is the first time such a systematic analysis has been reported, giving insight into the behavior of HHDHs in nonconventional media and opening new opportunities for the future biocatalytic applications.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Kemijsko inženjerstvo

POVEZANOST RADA