title: Implication of substrate-assisted catalysis on improving lipase activity or enantioselectivity in organic solvents.
abstract: In comparison with the biocatalyst engineering and medium engineering approaches, very few examples have been reported on using the substrate engineering approach such as substrate-assisted catalysis (SAC) for naturally occurring or engineered lipases and serine proteases to improve the enzyme activity and enantioselectivity. By employing lipase-catalyzed hydrolysis of (R,S)-naproxen esters in water-saturated isooctane as the model system, we demonstrate the proton shuttle device to the leaving alcohol of the substrate as a new means of SAC to effectively improve the lipase activity or enantioselectivity. The result cannot only provide a strong evidence for the rate-limiting proton transfer for the bond-breaking of tetrahedron intermediate of the acylation step, but also sheds light for performing the hydrolysis, transesterification or aminolysis in organic solvents for the ester substrate that originally lipases cannot catalyze, but now can after introducing the device.
authors.affiliation: Institute of Biochemical and Biomedical Engineering, Chang Gung University, Kwei-Shan Tao-Yuan, 33302, Taiwan. tsai@mail.cgu.edu.tw
authors.forename: Shau-Wei
authors.initials: SW
authors.lastname: Tsai
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Chen
authors.forename: Hung-Shien
authors.initials: HS
authors.lastname: Yang
authors.forename: I-Son
authors.initials: IS
authors.lastname: Ng
authors.forename: Teh-Liang
authors.initials: TL
authors.lastname: Chen
mesh_terms: D016956:Burkholderia cepacia / Q000201:enzymology; D002175:Candida / Q000201:enzymology; D029441:Carica / Q000201:enzymology; D020134:Catalytic Domain; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism*; D009288:Naproxen / Q000737:chemistry / Q000378:metabolism; D012997:Solvents; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D012997:Solvents; D009288:Naproxen; D008049:Lipase