Engineering the substrate-binding domain of an esterase enhances its hydrolytic activity toward fatty acid esters

2014 ◽  
Vol 49 (12) ◽  
pp. 2101-2106 ◽  
Author(s):  
Young-A Lee ◽  
Eun-Yeong Jeon ◽  
Sun-Mee Lee ◽  
Uwe T. Bornscheuer ◽  
Jin-Byung Park
2006 ◽  
Vol 72 (11) ◽  
pp. 7331-7338 ◽  
Author(s):  
Tomohiro Hiraishi ◽  
Yoko Hirahara ◽  
Yoshiharu Doi ◽  
Mizuo Maeda ◽  
Seiichi Taguchi

ABSTRACT Poly[(R)-3-hydroxybutyrate] (PHB) depolymerase from Ralstonia pickettii T1 (PhaZRpiT1) adsorbs to denatured PHB (dPHB) via its substrate-binding domain (SBD) to enhance dPHB degradation. To evaluate the amino acid residues participating in dPHB adsorption, PhaZRpiT1 was subjected to a high-throughput screening system consisting of PCR-mediated random mutagenesis targeted to the SBD gene and a plate assay to estimate the effects of mutations in the SBD on dPHB degradation by PhaZRpiT1. Genetic analysis of the isolated mutants with lowered activity showed that Ser, Tyr, Val, Ala, and Leu residues in the SBD were replaced by other residues at high frequency. Some of the mutant enzymes, which contained the residues replaced at high frequency, were applied to assays of dPHB degradation and adsorption, revealing that those residues are essential for full activity of both dPHB degradation and adsorption. These results suggested that PhaZRpiT1 adsorbs on the surface of dPHB not only via hydrogen bonds between hydroxyl groups of Ser in the enzyme and carbonyl groups in the PHB polymer but also via hydrophobic interaction between hydrophobic residues in the enzyme and methyl groups in the PHB polymer. The L441H enzyme, which displayed lower dPHB degradation and adsorption abilities, was purified and applied to a dPHB degradation assay to compare it with the wild-type enzyme. The kinetic analysis of the dPHB degradation suggested that lowering the affinity of the SBD towards dPHB causes a decrease in the dPHB degradation rate without the loss of its hydrolytic activity for the polymer chain.


2014 ◽  
Vol 31 (2) ◽  
pp. 95-101
Author(s):  
Xiaobo YAN ◽  
Shaoming WU ◽  
Nan LI ◽  
Huadong LV ◽  
Wusheng FU

1994 ◽  
Vol 59 (4) ◽  
pp. 833-840
Author(s):  
Slavomír Pirkl

The phase transitions and effective optical rotary power of saturated and monounsaturated aliphatic esters of cholesterol with 18 and 22 carbon atoms in the chain have been described. The effect of cis/trans isomerism on these properties is discussed.


1992 ◽  
Vol 70 (6) ◽  
pp. 448-454 ◽  
Author(s):  
Ewa Świeżewska ◽  
T. Chojnacki ◽  
W. J. Jankowski ◽  
K. Singh ◽  
J. Olsson

The long chain polyprenols composed of 30 and more isoprene units from leaves of plants belonging to the genera Potentilla and Rosa have been described. They occur in the form of fatty acid esters. The composition of polyprenol mixture was species dependent and its content reached ca. 0.5% wet weight. Large scale preparation of individual polyprenols from a natural polyprenol mixture was performed using time-extended liquid chromatography on the hydrophobic gel Lipidex-5000.Key words: long chain polyprenols, Rosaceae.


Author(s):  
Marija Iljina ◽  
Hisham Mazal ◽  
Pierre Goloubinoff ◽  
Inbal Riven ◽  
Gilad Haran

Author(s):  
R E Pauls ◽  
B Pease

Abstract An ionic liquid (IL) 111 column was compared with other commonly employed stationary phases including polydimethyl siloxane and polyethylene glycol for the separation of fatty acid monomethyl and dimethyl esters. The fatty acid esters employed in this study were derived from metathesis reactions of vegetable oils both with and without olefins. The IL 111 column demonstrated enhanced performance compared with conventional columns for the separation of these esters. These advantages included significantly enhanced retention of dimethyl esters relative to monomethyl esters, excellent cis/trans isomer separation and the ability to analyze higher carbon number dimethyl esters. As a result, these columns are highly suited for the analysis of mixtures of mono- and dimethyl fatty acid esters found in lipid metathesis reaction products or to determine monofunctional impurities in samples of commercial dimethyl esters.


ACS Omega ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 3227-3231
Author(s):  
Chizuru Kogame-Asahara ◽  
Hitomi Iguchi ◽  
Kenichiro Honda ◽  
Hajime Shigemitsu ◽  
Toshiyuki Kida

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