Effect of ionic liquid properties on lipase stabilization under microwave irradiation

Zhao, Hua; Baker, Gary A.; Song, Zhiyan; Olubajo, Olarongbe; Zanders, Lavezza; Campbell, Sophia M.

doi:10.1016/j.molcatb.2008.08.006

Cited by 109 publications

(63 citation statements)

References 117 publications

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“…However, since enzymes are not soluble in most common ILs, enzyme molecules are suspended in reaction media at low water contents (for example, CALB is known to be active in the absence of water 59,65 ); as a result, IL network theory is not appropriate for understanding these enzymatic reactions.…”

Section: Il Networkmentioning

confidence: 99%

Methods for stabilizing and activating enzymes in ionic liquids—a review

Zhao

2010

J of Chemical Tech & Biotech

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Ionic liquids (ILs) have evolved as a new type of non-aqueous solvents for biocatalysis, mainly due to their unique and tunable physical properties. A number of recent review papers have described a variety of enzymatic reactions conducted in IL solutions; on the other hand, it is important to systematically analyze methods that have been developed for stabilizing and activating enzymes in ILs. This review discusses the biocatalysis in ILs from two unique aspects (1) factors that impact the enzyme's activity and stability, (2) methods that have been adopted or developed to activate and/or stabilize enzymes in ionic media. Factors that may influence the catalytic performance of enzymes include IL polarity, hydrogen-bond basicity/anion nucleophilicity, IL network, ion kosmotropicity, viscosity, hydrophobicity, the enzyme dissolution, and surfactant effect. To improve the enzyme's activity and stability in ILs, major methods being explored include the enzyme immobilization (on solid support, sol-gel, or CLEA), physical or covalent attachment to PEG, rinsing with n-propanol methods (PREP and EPRP), water-in-IL microemulsions, IL coating, and the design of enzyme-compatible ionic solvents. It is exciting to notice that new ILs are being synthesized to be more compatible with enzymes. To utilize the full potential of ILs, it is necessary to further improve these methods for better enzyme compatibility. This is what has been accomplished in the field of biocatalysis in conventional organic solvents. c 2010 Society of Chemical Industry Keywords: ionic liquid; enzyme activity; enzyme stabilization; immobilization; biocatalysis NOTATION CationsBMIM + = 1-butyl-3-methylimidazolium C 2 OC 1 MIM + = 1-(2-methoxy)ethyl-3-methylimidazolium C 2 OHMIM + = 1-(2-hydroxy)ethyl-3-methylimidazolium EMIM + = 1-ethyl-3-methylimidazolium

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Section: Il Networkmentioning

confidence: 99%

Methods for stabilizing and activating enzymes in ionic liquids—a review

Zhao

2010

J of Chemical Tech & Biotech

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342

241

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“…脂肪酶催化酯类合成过程中, 需要少量的水分子维持脂肪酶的空间构象(机理见图 1) [40] . 在 "疏水离子液体 -酶" 组成的微环境中(图 1a), 离子液体的疏水作用导致酶周围的水分子层具有比离子液体更高的介电常数, 使得水分子不易与酶分离, 空间结构稳定.…”

Section: 影响脂肪酶的微环境unclassified

“…在 "疏水离子液体 -酶" 组成的微环境中(图 1a), 离子液体的疏水作用导致酶周围的水分子层具有比离子液体更高的介电常数, 使得水分子不易与酶分离, 空间结构稳定. 在一定的范围内, 离子液体的疏水性越大, 水分子与酶的相互作用力越强, 酶的空间结构越稳定 [40] ; 但当离子液体的疏水性超过界限值后, 酶活性随着离子液体疏水性增大而降低, 原因在于离子液体的疏水性过高会抑制底物与酶分子的相互接触, 降低底物在离子液体中的溶解度, 阻碍底物与酶分子的相互作用 [41] . 而"在亲水性离子液体-酶"组成的微环境中(图 1b), 离子液体由于本身具有更高的介电常数, 从而取代结合在酶表面的水分子, 引起脂肪酶的肽链解折叠, 最终表现为酶的活性降低甚至失活 [3] .…”

Section: 影响脂肪酶的微环境unclassified

“…表 3 机械搅拌和超声作用下不同酯类的产率 [65] ; 此外, 脂肪酶多为电偶极子, 在微波电场中电偶极子会产生强烈振动, 分子之间增大了相互碰撞, 从而在脂肪酶微环境中产生较多的热量, 提高反应的速率 [66] . 需要注意的是, 微波对脂肪酶活力的影响并不明显 [40] . 此外, Lamare 等 [67] 比较了在反应前和反应过程中两种情况下对脂肪酶微波处理, 结果表明在反应过程中微波处理的脂肪酶稳定性更强.…”

Section: 场/反应器强化酶促酯类合成unclassified

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Progress of Lipase-Catalyzed Ester Synthesis in Ionic Liquid

Li¹,

Wang²,

Leixia³

et al. 2012

Chin. J. Org. Chem.

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“…2. (Kaar et al, 2003;Ulbert et al, 2004;Zhao et al, 2008), respectively, proved to be adequate reaction media for lipase-catalyzed acylation of (R,S)-1-phenylethanol with vinyl acetate. Enzyme activity increased with the decrease in logP values of ILs and the highest enzyme activity was observed in [bmim] [BF 4 ] with logP value -2.44.…”

Section: Gas Chromatography Analysis (Gc Analysis)mentioning

confidence: 99%