Immobilization of Lipases for Use in Non-Aqueous Reaction Systems

Bosley, John A.; Peilow, Alan D.

doi:10.1007/978-3-0348-8472-3_4

Cited by 11 publications

(7 citation statements)

References 29 publications

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“…Table 1 shows the variation in immobilization efficiency with different quantities of enzyme, to which the same amount of nanotubes was exposed, with the highest immobilization efficiency obtained being 0.53. It has been reported that in the case of some lipases, the presence of an inert protein, such as albumins, gave higher immobilization efficiencies with hydrophobic surfaces like accurel™ [ 19 ].…”

Section: Resultsmentioning

confidence: 99%

“…Given the high surface area of nanotubes, 2.9 units (entry 3 Table 1 , corresponding to immobilization efficiency of 0.53) constitute a very low protein load region. As pointed out by Bosley and Pielow [ 19 ], in such situations the enzyme attempts to maximize its contact with the surface, leading to undesirable conformational changes and hence loss of activity. This is overcome by the addition of other proteins that block the 'high affinity' sites on the support, or simply reduce the surface area available to the enzyme.…”

Section: Resultsmentioning

confidence: 99%

“…The kinetic resolution of racemates to obtain chiral compounds has emerged as a major application of enzymes [ 15 - 19 , 29 ]. Table 4 shows that free enzyme showed poor transesterification rates during kinetic resolution of (±) 1-phenyl ethanol.…”

Section: Resultsmentioning

confidence: 99%

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Enhancement of lipase activity in non-aqueous media upon immobilization on multi-walled carbon nanotubes

Shah

Solanki

Gupta

2007

Chemistry Central Journal

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BackgroundImmobilization of biologically active proteins on nanosized surfaces is a key process in bionanofabrication. Carbon nanotubes with their high surface areas, as well as useful electronic, thermal and mechanical properties, constitute important building blocks in the fabrication of novel functional materials.ResultsLipases from Candida rugosa (CRL) were found to be adsorbed on the multiwalled carbon nanotubes with very high retention of their biological activity (97%). The immobilized biocatalyst showed 2.2- and 14-fold increases in the initial rates of transesterification activity in nearly anhydrous hexane and water immiscible ionic liquid [Bmim] [PF6] respectively, as compared to the lyophilized powdered enzyme. It is presumed that the interaction with the hydrophobic surface of the nanotubes resulted in conformational changes leading to the 'open lid' structure of CRL. The immobilized enzyme was found to give 64% conversion over 24 h (as opposed to 14% with free enzyme) in the formation of butylbutyrate in nearly anhydrous hexane. Similarly, with ionic liquid [Bmim] [PF6], the immobilized enzyme allowed 71% conversion as compared to 16% with the free enzyme. The immobilized lipase also showed high enantioselectivity as determined by kinetic resolution of (±) 1-phenylethanol in [Bmim] [PF6]. While free CRL gave only 5% conversion after 36 h, the immobilized enzyme resulted in 37% conversion with > 99% enantiomeric excess. TEM studies on the immobilized biocatalyst showed that the enzyme is attached to the multiwalled nanotubes.ConclusionSuccessful immobilization of enzymes on nanosized carriers could pave the way for reduced reactor volumes required for biotransformations, as well as having a use in the construction of miniaturized biosensensor devices.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Enhancement of lipase activity in non-aqueous media upon immobilization on multi-walled carbon nanotubes

Shah

Solanki

Gupta

2007

Chemistry Central Journal

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“…So, as the amount of protein precipitating was same in each case, protein in ECCN 4 or ECCN 5 is spread over a larger surface. Enzyme molecules having excess immobilization surface available are known to show decrease in catalytic activity [ 35 ]. So, ECCN 3 represents the best tradeoff between having enough nanoparticles to precipitate on (or coat on) versus decrease in enzyme activity due to excess large immobilization surface.…”

Section: Resultsmentioning

confidence: 99%

Alpha chymotrypsin coated clusters of Fe3O4nanoparticles for biocatalysis in low water media

Mukherjee

Gupta

2012

Chemistry Central Journal

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BackgroundEnzymes in low water containing non aqueous media are useful for organic synthesis. For example, hydrolases in such media can be used for synthetic purposes. Initial work in this area was carried out with lyophilized powders of enzymes. These were found to have poor activity. Drying (removing bulk water) by precipitation turned out to be a better approach. As enzymes in such media are heterogeneous catalysts, spreading these precipitates over a large surface gave even better results. In this context, nanoparticles with their better surface to volume ratio provide obvious advantage. Magnetic nanoparticles have an added advantage of easy separation after the reaction. Keeping this in view, alpha chymotrypsin solution in water was precipitated over a stirred population of Fe3O4 nanoparticles in n-propanol. This led to alpha chymotrypsin activity coated over clusters of Fe3O4 nanoparticles. These preparations were found to have quite high transesterification activity in low water containing n-octane.ResultsPrecipitation of alpha chymotrypsin over a stirred suspension of Fe3O4 nanoparticles (3.6 nm diameter) led to the formation of enzyme coated clusters of nanoparticles (ECCNs). These clusters were also magnetic and their hydrodynamic diameter ranged from 1.2- 2.6 microns (as measured by dynamic light scattering). Transmission electron microscopy (TEM), showed that these clusters had highly irregular shapes. Transesterification assay of various clusters in anhydrous n-octane led to optimization of concentration of nanoparticles in suspension during precipitation. Optimized design of enzyme coated magnetic clusters of nanoparticles (ECCN 3) showed the highest initial rate of 465 nmol min-1 mg-1protein which was about 9 times higher as compared to the simple precipitates with an initial rate of 52 nmol min-1 mg-1 protein.Circular Dichroism (CD)(with a spinning cell accessory) showed that secondary structure content of the alpha Chymotrypsin in ECCN 3 [15% α-helix, 37% β-sheet and 48% random coil] was identical to the simple precipitates of alpha chymotrypsin.ConclusionA strategy for obtaining a high activity preparation of alpha chymotrypsin for application in low water media is described. Such high activity biocatalysts are useful in organic synthesis.

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“…Immobilization has also been suggested as a means to increase surface area and enzyme stability in nonaqueous media. 1 Propyl gallate (PG) is widely used as a food additive antioxidant. Tannin acyl hydrolases (EC 3.1.1.20), commonly referred to as tannases, are inducible enzymes produced mainly by fungi.…”

Section: Introductionmentioning

confidence: 99%

Microencapsulation of tannase by chitosan–alginate complex coacervate membrane: synthesis of antioxidant propyl gallate in biphasic media

2004

J of Chemical Tech & Biotech

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Tannase microencapsulated by a chitosan-alginate complex coacervate membrane has been used for synthesis of the food additive antioxidant, propyl gallate. Matrix experiments using standard L9 orthogonal array were used to evaluate the effects of the microencapsulation process on the synthesis of propyl gallate in biphasic media. The statistical analysis of signal-to-noise ratio and decomposition of variance (ANOVA) were performed to estimate the optimum levels and determine the relative magnitude of the effects of the three control factors which were chitosan, alginate and hardening time.

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Immobilization of Lipases for Use in Non-Aqueous Reaction Systems

Cited by 11 publications

References 29 publications

Enhancement of lipase activity in non-aqueous media upon immobilization on multi-walled carbon nanotubes

Enhancement of lipase activity in non-aqueous media upon immobilization on multi-walled carbon nanotubes

Alpha chymotrypsin coated clusters of Fe3O4nanoparticles for biocatalysis in low water media

Microencapsulation of tannase by chitosan–alginate complex coacervate membrane: synthesis of antioxidant propyl gallate in biphasic media

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