Limits...
Combination of oxyanion Gln114 mutation and medium engineering to influence the enantioselectivity of thermophilic lipase from Geobacillus zalihae.

Wahab RA, Basri M, Rahman MB, Rahman RN, Salleh AB, Leow TC - Int J Mol Sci (2012)

Bottom Line: The mutation improved enantioselectivity in Q114M over the wild-type, while enantioselectivity in Q114L was reduced.Molecular sieves employed as desiccant were found to adversely affect catalysis in the lipase variants, particularly in Q114M.The higher desiccant loading also increased viscosity in the reaction and further reduced the efficiency of the lipase-catalyzed esterifications.

View Article: PubMed Central - PubMed

Affiliation: Enzyme and Microbial Technology Group, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia; E-Mail: basya@science.upm.edu.my ; Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor 81310, Malaysia.

ABSTRACT
The substitution of the oxyanion Q114 with Met and Leu was carried out to investigate the role of Q114 in imparting enantioselectivity on T1 lipase. The mutation improved enantioselectivity in Q114M over the wild-type, while enantioselectivity in Q114L was reduced. The enantioselectivity of the thermophilic lipases, T1, Q114L and Q114M correlated better with log p as compared to the dielectric constant and dipole moment of the solvents. Enzyme activity was good in solvents with log p < 3.5, with the exception of hexane which deviated substantially. Isooctane was found to be the best solvent for the esterification of (R,S)-ibuprofen with oleyl alcohol for lipases Q114M and Q114L, to afford E values of 53.7 and 12.2, respectively. Selectivity of T1 was highest in tetradecane with E value 49.2. Solvents with low log p reduced overall lipase activity and dimethyl sulfoxide (DMSO) completely inhibited the lipases. Ester conversions, however, were still low. Molecular sieves employed as desiccant were found to adversely affect catalysis in the lipase variants, particularly in Q114M. The higher desiccant loading also increased viscosity in the reaction and further reduced the efficiency of the lipase-catalyzed esterifications.

No MeSH data available.


The effects of desiccant loading on e.ep% and E values in the T1 lipase, Q114L and Q114-M catalyzed esterification of ibuprofen. The reactions were carried out in isooctane (8 mL), lyophilized lipase (5 mg) (R,S)-ibuprofen (0.8252 g, 4 mmole) and oleyl alcohol (1.872 mL, 6 mmole) at 50 °C and stirred at 200 rpm. The amount of added desiccant was examined at 0, 2 and 4 mg loading. (A) T1; (B) Q114L and (C) Q114M.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC3472768&req=5

f4-ijms-13-11666: The effects of desiccant loading on e.ep% and E values in the T1 lipase, Q114L and Q114-M catalyzed esterification of ibuprofen. The reactions were carried out in isooctane (8 mL), lyophilized lipase (5 mg) (R,S)-ibuprofen (0.8252 g, 4 mmole) and oleyl alcohol (1.872 mL, 6 mmole) at 50 °C and stirred at 200 rpm. The amount of added desiccant was examined at 0, 2 and 4 mg loading. (A) T1; (B) Q114L and (C) Q114M.

Mentions: The E values and e.ep% of T1, Q114L and Q114M-catalyzed esterification with respect to the amount of desiccant loading are illustrated in Figure 4. In all reactions catalyzed by the three lipases, e.ep% reduced as desiccant loading was increased. Selectivity was highest for reactions without added desiccant with Q114M exhibiting the highest E values—between 29.1 and 53.4. Selectivity profiles for T1 and Q114L under variable desiccant loading were quite similar, except selectivity, which was marginally higher in the former at E values 11.7 to 13.8, while the latter attained E values 8.6 to 11.8.


Combination of oxyanion Gln114 mutation and medium engineering to influence the enantioselectivity of thermophilic lipase from Geobacillus zalihae.

Wahab RA, Basri M, Rahman MB, Rahman RN, Salleh AB, Leow TC - Int J Mol Sci (2012)

The effects of desiccant loading on e.ep% and E values in the T1 lipase, Q114L and Q114-M catalyzed esterification of ibuprofen. The reactions were carried out in isooctane (8 mL), lyophilized lipase (5 mg) (R,S)-ibuprofen (0.8252 g, 4 mmole) and oleyl alcohol (1.872 mL, 6 mmole) at 50 °C and stirred at 200 rpm. The amount of added desiccant was examined at 0, 2 and 4 mg loading. (A) T1; (B) Q114L and (C) Q114M.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472768&req=5

f4-ijms-13-11666: The effects of desiccant loading on e.ep% and E values in the T1 lipase, Q114L and Q114-M catalyzed esterification of ibuprofen. The reactions were carried out in isooctane (8 mL), lyophilized lipase (5 mg) (R,S)-ibuprofen (0.8252 g, 4 mmole) and oleyl alcohol (1.872 mL, 6 mmole) at 50 °C and stirred at 200 rpm. The amount of added desiccant was examined at 0, 2 and 4 mg loading. (A) T1; (B) Q114L and (C) Q114M.
Mentions: The E values and e.ep% of T1, Q114L and Q114M-catalyzed esterification with respect to the amount of desiccant loading are illustrated in Figure 4. In all reactions catalyzed by the three lipases, e.ep% reduced as desiccant loading was increased. Selectivity was highest for reactions without added desiccant with Q114M exhibiting the highest E values—between 29.1 and 53.4. Selectivity profiles for T1 and Q114L under variable desiccant loading were quite similar, except selectivity, which was marginally higher in the former at E values 11.7 to 13.8, while the latter attained E values 8.6 to 11.8.

Bottom Line: The mutation improved enantioselectivity in Q114M over the wild-type, while enantioselectivity in Q114L was reduced.Molecular sieves employed as desiccant were found to adversely affect catalysis in the lipase variants, particularly in Q114M.The higher desiccant loading also increased viscosity in the reaction and further reduced the efficiency of the lipase-catalyzed esterifications.

View Article: PubMed Central - PubMed

Affiliation: Enzyme and Microbial Technology Group, Faculty of Science, Universiti Putra Malaysia, Serdang, Selangor 43400, Malaysia; E-Mail: basya@science.upm.edu.my ; Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor 81310, Malaysia.

ABSTRACT
The substitution of the oxyanion Q114 with Met and Leu was carried out to investigate the role of Q114 in imparting enantioselectivity on T1 lipase. The mutation improved enantioselectivity in Q114M over the wild-type, while enantioselectivity in Q114L was reduced. The enantioselectivity of the thermophilic lipases, T1, Q114L and Q114M correlated better with log p as compared to the dielectric constant and dipole moment of the solvents. Enzyme activity was good in solvents with log p < 3.5, with the exception of hexane which deviated substantially. Isooctane was found to be the best solvent for the esterification of (R,S)-ibuprofen with oleyl alcohol for lipases Q114M and Q114L, to afford E values of 53.7 and 12.2, respectively. Selectivity of T1 was highest in tetradecane with E value 49.2. Solvents with low log p reduced overall lipase activity and dimethyl sulfoxide (DMSO) completely inhibited the lipases. Ester conversions, however, were still low. Molecular sieves employed as desiccant were found to adversely affect catalysis in the lipase variants, particularly in Q114M. The higher desiccant loading also increased viscosity in the reaction and further reduced the efficiency of the lipase-catalyzed esterifications.

No MeSH data available.