Improvement of enantioselectivity and stability of Klebsiella oxytoca hydrolase immobilized on Eupergit C 250L

Wang, Pei-Yun; Tsai, Shau‐Wei; Chen, Teh-Liang

doi:10.1016/j.jbiotec.2008.07.887

Cited by 5 publications

(7 citation statements)

References 10 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The enzyme bound in terms of free SNSM-87 was determined as 76.4 mg per g of the immobilized support (Method 2 in Wang et al, 2008). This is confirmed from the weight increase of 36.4 mg per g of the immobilized support and the decrease of band absorption at about 907 cm À1 for the asymmetric stretching of epoxide ring in FTIR spectra (Fig.…”

Section: Enzyme Immobilizationmentioning

confidence: 60%

“…Unless specified, immobilizations were carried out in 10 mL phosphate buffers (1 M, pH 7) containing 100 mg of Eupergit C 250 L and 10 mg SNSM-87 at 258C and 150 rpm for 4 h. The supports were filtered, washed in succession with the buffer (3 Â 10 mL) and deionized water (10 mL) each for 0.5 h, lyophilized for 24 h, weighted, and then stored at 48C prior to use. The enzyme bound in terms of free SNSM-87 was determined as 76.4 mg per g of the immobilized support (Method 2 in Wang et al, 2008). This is confirmed from the weight increase of 36.4 mg per g of the immobilized support and the decrease of band absorption at about 907 cm À1 for the asymmetric stretching of epoxide ring in FTIR spectra ( Fig.…”

Section: Enzyme Immobilizationmentioning

confidence: 60%

“…Therefore, an estimation of the ionization constants for the imidazolium of catalytic histidine at the presence of substrates is needed. Figure S3 illustrates effects of changing pH on relative enzyme activity of (R)-or (S)-ethyl mandelate at 558C (Wang et al, 2008). Since K ÃÃ mR ) ðS R Þ and K ÃÃ mS ) ðS S Þ for both enzyme preparations at the present reaction conditions (Tables I and III), this figure can be regarded as effects of varying pH on the relative specificity constants k 2R /K mR and k 2S /K mS .…”

Section: Kinetic Analysis For (Rs)-mandelatesmentioning

confidence: 97%

See 2 more Smart Citations

Improvements of enzyme activity and enantioselectivity via combined substrate engineering and covalent immobilization

Wang

Tsai

Chen

2008

Biotech & Bioengineering

Self Cite

View full text Add to dashboard Cite

Esterases, lipases, and serine proteases have been applied as versatile biocatalysts for preparing a variety of chiral compounds in industry via the kinetic resolution of their racemates. In order to meet this requirement, three approaches of enzyme engineering, medium engineering, and substrate engineering are exploited to improve the enzyme activity and enantioselectivity. With the hydrolysis of (R,S)-mandelates in biphasic media consisting of isooctane and pH 6 buffer at 55 degrees C as the model system, the strategy of combined substrate engineering and covalent immobilization leads to an increase of enzyme activity and enantioselectivity from V(S)/(E(t)) = 1.62 mmol/h g and V(S)/V(R) = 43.6 of (R,S)-ethyl mandelate (1) for a Klebsiella oxytoca esterase (named as SNSM-87 from the producer) to 16.7 mmol/h g and 867 of (R,S)-2-methoxyethyl mandelate (4) for the enzyme immobilized on Eupergit C 250L. The analysis is then extended to other (R,S)-2-hydroxycarboxylic acid esters, giving improvements of the enzyme performance from V(S)/(E(t)) = 1.56 mmol/h g and V(S)/V(R) = 41.9 of (R,S)-ethyl 3-chloromandelate (9) for the free esterase to 39.4 mmol/h g and 401 of (R,S)-2-methoxyethyl 3-chloromandelate (16) for the immobilized enzyme, V(S)/(E(t)) = 5.46 mmol/h g and V(S)/V(R) = 8.27 of (R,S)-ethyl 4-chloromandelate (10) for free SNSM-87 to 33.5 mmol/h g and 123 of (R,S)-methyl 4-chloromandelate (14) for the immobilized enzyme, as well as V(S)/(E(t)) = 3.0 mmol/h g and V(S)/V(R) = 7.94 of (R,S)-ethyl 3-phenyllactate (11) for the free esterase to 40.7 mmol/h g and 158 of (R,S)-2-methoxyethyl 3-phenyllactate (18) for the immobilized enzyme. The great enantioselectivty enhancement is rationalized from the alteration of ionization constants of imidazolium moiety of catalytic histidine for both enantiomers and conformation distortion of active site after the covalent immobilization, as well as the selection of leaving alcohol moiety via substrate engineering approach.

show abstract

Section: Enzyme Immobilizationmentioning

confidence: 60%

Section: Enzyme Immobilizationmentioning

confidence: 60%

Section: Kinetic Analysis For (Rs)-mandelatesmentioning

confidence: 97%

See 1 more Smart Citation

Improvements of enzyme activity and enantioselectivity via combined substrate engineering and covalent immobilization

Wang

Tsai

Chen

2008

Biotech & Bioengineering

Self Cite

View full text Add to dashboard Cite

show abstract

“…Except for using 1 mM of 1 as the substrate, detailed procedures for determining Lipase PS immobilized on the support, i.e. 314 mg/(g immobilized Eupergit C 250L) and 26.2 mg/(g immobilized Sepabeads @ EC-HA) based on the crude enzyme, are referred to and Wang et al (2008a).…”

Section: Enzyme Immobilizationmentioning

confidence: 99%

Lipase-catalyzed hydrolytic resolution of (R,S)-3-hydroxy-3-phenylpropionates in biphasic media

Cho

Wang

Tsai

2011

Journal of the Taiwan Institute of Chemical Engineers

Self Cite

View full text Add to dashboard Cite

“…Είναι γνωστό ότι οι ιδιότητες των ακινητοποιημένων ενζύμων πολλές φορές διαφέρουν από αυτές των ελεύθερων [Wang et al, 2008;Kumari et al, 2008]. Οι διαφορές αυτές καθορίζονται από: α) τη διαμόρφωση του πρωτεϊνικού μορίου στο χώρο, β) το υλικό στήριξης, γ) τη μέθοδο και δ) τις συνθήκες ακινητοποίησης.…”

Section: επίδραση ακινητοποίησης στα καταλυτικά χαρακτηριστικάunclassified

Ανάπτυξη Βιοκαταλυτικών Διεργασιών Σε Μη Συμβατικά Μέσα Για Την Τροποποίηση Ενώσεων Φυτικής Προέλευσης Με Στόχο Την Αναβάθμιση Των Ιδιοτήτων Τους

Τζιάλλα¹

View full text Add to dashboard Cite

Improvement of enantioselectivity and stability of Klebsiella oxytoca hydrolase immobilized on Eupergit C 250L

Cited by 5 publications

References 10 publications

Improvements of enzyme activity and enantioselectivity via combined substrate engineering and covalent immobilization

Improvements of enzyme activity and enantioselectivity via combined substrate engineering and covalent immobilization

Lipase-catalyzed hydrolytic resolution of (R,S)-3-hydroxy-3-phenylpropionates in biphasic media

Ανάπτυξη Βιοκαταλυτικών Διεργασιών Σε Μη Συμβατικά Μέσα Για Την Τροποποίηση Ενώσεων Φυτικής Προέλευσης Με Στόχο Την Αναβάθμιση Των Ιδιοτήτων Τους

Contact Info

Product

Resources

About