Enzyme-catalyzed resolution of aromatic ring fused cyclic tertiary alcohols

Özdemirhan, Devrim; Sezer, Serdar; Sönmez, Yasemin

doi:10.1016/j.tetasy.2008.12.002

Cited by 28 publications

(20 citation statements)

References 21 publications

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“…Similarly, lipase–CLEAs have been prepared from, inter alia , C. antarctica lipase A (Özdemirhan et al 2008 ), Burkholderia cepacia (formerly known as Pseudomonas cepacia ) (Kumari et al 2007 ; Majumder et al 2008 ; Hara et al 2008 ), Candida rugosa (Yu et al 2006 ; Kartal et al 2011 ), and a Pseudomonas sp. lipase (Zhao et al 2008 ).…”

Section: Hydrolase Cleasmentioning

confidence: 99%

Characteristic features and biotechnological applications of cross-linked enzyme aggregates (CLEAs)

Sheldon

2011

Appl Microbiol Biotechnol

450

313

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Cross-linked enzyme aggregates (CLEAs) have many economic and environmental benefits in the context of industrial biocatalysis. They are easily prepared from crude enzyme extracts, and the costs of (often expensive) carriers are circumvented. They generally exhibit improved storage and operational stability towards denaturation by heat, organic solvents, and autoproteolysis and are stable towards leaching in aqueous media. Furthermore, they have high catalyst productivities (kilograms product per kilogram biocatalyst) and are easy to recover and recycle. Yet another advantage derives from the possibility to co-immobilize two or more enzymes to provide CLEAs that are capable of catalyzing multiple biotransformations, independently or in sequence as catalytic cascade processes.

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Section: Hydrolase Cleasmentioning

confidence: 99%

Characteristic features and biotechnological applications of cross-linked enzyme aggregates (CLEAs)

Sheldon

2011

Appl Microbiol Biotechnol

450

313

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“…But nowadays a carrier‐free immobilization approach has attracted more attention due to its clear advantages such as a highly concentrated enzyme activity in the immobilized form, high stability, and low production costs due to the omission of an additional carrier 20. Among the carrier‐free immobilization techniques, CLEA (crosslinked enzyme aggregates) is a rather simple example as developed by Cao et al21 The preparation of CLEAs of a wide variety of enzymes22 including various lipases23–34 has been described. The technique involves the precipitation of the enzyme followed by crosslinking of the precipitated enzyme aggregates with a bifunctional crosslinking agent such as glutaraldehyde.…”

Section: Introductionmentioning

confidence: 99%

Crosslinked aggregates of Rhizopus oryzae lipase as industrial biocatalysts: Preparation, optimization, characterization, and application for enantioselective resolution reactions

Kartal

Kilinc

2012

Biotechnology Progress

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Lipase from Rhizopus oryzae (ROL) was immobilized as crosslinked enzyme aggregate (CLEA) via precipitation with ammonium sulfate and simultaneous crosslinking with glutaraldehyde. The optimum conditions of the immobilization process were determined. Lipase CLEAs showed a twofold increase in activity when Tween 80-pretreated lipase was used for CLEA preparation. CLEAs were shown to have several advantages compared to free lipase. CLEAs were more stable at 50°C and 60°C as well as for a wide range of pH. After incubation at 50°C, CLEA showed 74% of initial activity whereas free enzyme was totally inactivated. Reduction of Schiff bases has been performed for the first time in the CLEA preparation process significantly improving the chemically modified CLEAs' reusability, thus providing an enzyme with high potential for recycling even under aqueous reaction conditions where enzyme leakage is, in general, one of the major problems. The CLEA retained 91% activity after 10 cycles in aqueous medium. The immobilized enzyme was used for kinetic resolution reactions. Results showed that immobilization had an enhancing effect on the conversion (c) as well as on the enantiomeric ratio (E). ROL CLEA displayed five times higher enantioselectivity for the hydrolysis of (R,S)-1-phenylethyl acetate and likewise 1.5 times higher enantioselectivity for the transesterification of racemic (R-S)-1-phenylethanol with vinylacetate.

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“…15,22 CAL-A has been shown to exhibit many unique catalytic properties, such as substrate preference for trans-fatty acids and the ability to catalyze highly enantioselective acylation reactions of bulky sterically hindered secondary and tertiary alcohols which are not usually accepted as substrates by lipases. [23][24][25][26][27][28][29] Of specific interest to this study, CAL-A preparations have also been shown to catalyze secondary Nacylation of a-amino esters, 30-32 and a range of other a-and bamino esters in organic solvents. [14][15][16] All these features make CAL-A a potential candidate for protein engineering.…”

Section: Introductionmentioning

confidence: 99%

Formation and hydrolysis of amide bonds by lipase A from Candida antarctica; exceptional features

et al. 2010

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Various commercial lyophilized and immobilized preparations of lipase A from Candida antarctica (CAL-A) were studied for their ability to catalyze the hydrolysis of amide bonds in N-acylated alpha-amino acids, 3-butanamidobutanoic acid (beta-amino acid) and its ethyl ester. The activity toward amide bonds is highly untypical of lipases, despite the close mechanistic analogy to amidases which normally catalyze the corresponding reactions. Most CAL-A preparations cleaved amide bonds of various substrates with high enantioselectivity, although high variations in substrate selectivity and catalytic rates were detected. The possible role of contaminant protein species on the hydrolytic activity toward these bonds was studied by fractionation and analysis of the commercial lyophilized preparation of CAL-A (Cat#ICR-112, Codexis). In addition to minor impurities, two equally abundant proteins were detected, migrating on SDS-PAGE a few kDa apart around the calculated size of CAL-A. Based on peptide fragment analysis and sequence comparison both bands shared substantial sequence coverage with CAL-A. However, peptides at the C-terminal end constituting a motile domain described as an active-site flap were not identified in the smaller fragment. Separated gel filtration fractions of the two forms of CAL-A both catalyzed the amide bond hydrolysis of ethyl 3-butanamidobutanoate as well as the N-acylation of methyl pipecolinate. Hydrolytic activity towards N-acetylmethionine was, however, solely confined to the fractions containing the truncated form of CAL-A. These fractions were also found to contain a trace enzyme impurity identified in sequence analysis as a serine carboxypeptidase. The possible role of catalytic impurities versus the function of CAL-A in amide bond hydrolysis is further discussed in the paper.

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Enzyme-catalyzed resolution of aromatic ring fused cyclic tertiary alcohols

Cited by 28 publications

References 21 publications

Characteristic features and biotechnological applications of cross-linked enzyme aggregates (CLEAs)

Characteristic features and biotechnological applications of cross-linked enzyme aggregates (CLEAs)

Crosslinked aggregates of Rhizopus oryzae lipase as industrial biocatalysts: Preparation, optimization, characterization, and application for enantioselective resolution reactions

Formation and hydrolysis of amide bonds by lipase A from Candida antarctica; exceptional features

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