89378-61-0Relevant articles and documents
A one-step method for covalent bond immobilization of biomolecules on silica operated in aqueous solution
Sim, Yong-Kyun,Jung, Heetae,Kim, Su Hyun,Park, Jung-Woo,Park, Woo-Jin,Jun, Chul-Ho
, p. 7981 - 7985 (2018)
A simple, one-step method for covalent bond immobilization of biomolecules on silica operated in water is described. In the approach, an NHS-ester linked methallylsilane is utilized as a bifunctional linker to couple the biomolecule to the silica surface. Weak organic acid such as acetic acid activates the silica surface enough to react with bifunctional linker without destroying activity of biomolecule.
Two Approaches for CAL-B-Catalyzed Enantioselective Deacylation of a Set of α-Phenyl Ethyl Esters: Organic Solvent with Sodium Carbonate and Micro-aqueous Medium
Razi, Samra,Zeror, Saoussen,Merabet-Khelassi, Mounia,Kolodziej, Emilie,Toffano, Martial,Aribi-Zouioueche, Louisa
, p. 2603 - 2611 (2021/01/15)
Herein, we report an efficient enantioselective cleavage of the acyl- moiety of a set of α- phenyl ethyl esters with different chain-lengths catalyzed by lipase B from Candida antarctica (CAL-B) by comparing two reactional approaches: anhydrous media with sodium carbonates and micro-aqueous medium. The deacylation is performed in organic solvent, in the presence of Na2CO3 in the first case, and by addition of a drop of phosphate buffer solution pH 7 in the second. The results show the high efficiency of the deacylation in the presence of the sodium carbonate for the enzymatic resolution of all the esters and that in term of reactivity (31% ≤ conv ≤ 50%) and selectivity (E > 200). While, during the hydrolysis in micro-aqueous media, the conversion is strongly affected by the length of the acyl-chain side, the conversion decreases from conv = 50% with the 1-phenylethyl acetate 1a to conv = 19% with 1-phenyethyl dodecanoate 6a, and this, even if the selectivity remains high (E > 89). In both conditions, the lipase CAL-B shows a high enantioselectivities in favor of (R)-1-phenyl ethanol enantiomer (conv > 45%, E > 200) but the reactivity is modulated by the form and the size of the acyl-chain side. Graphic Abstract: [Figure not available: see fulltext.].
Improved Enantioselectivity of Subtilisin Carlsberg towards Secondary Alcohols by Protein Engineering
Dorau, Robin,G?rbe, Tamás,Svedendahl Humble, Maria
, p. 338 - 346 (2017/12/26)
Generally, the catalytic activity of subtilisin Carlsberg (SC) for transacylation reactions with secondary alcohols in organic solvent is low. Enzyme immobilization and protein engineering was performed to improve the enantioselectivity of SC towards secondary alcohols. Possible amino-acid residues for mutagenesis were found by combining available literature data with molecular modeling. SC variants were created by site-directed mutagenesis and were evaluated for a model transacylation reaction containing 1-phenylethanol in THF. Variants showing high E values (>100) were found. However, the conversions were still low. A second mutation was made, and both the E values and conversions were increased. Relative to that shown by the wild type, the most successful variant, G165L/M221F, showed increased conversion (up to 36 %), enantioselectivity (E values up to 400), substrate scope, and stability in THF.
