Esterases

Phythian, Sara J.

doi:10.1002/9783527620906.ch4

Cited by 8 publications

(3 citation statements)

References 154 publications

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“…Thus, precipitates were presumably formed because of papain-catalyzed hydrolysis of the copolymer films. Since papain exhibits esterase activity, it can not only attach amino acids onto the grafter but also hydrolyze the ester bonds of the copolymer, causing it to degrade. The 1 H NMR analysis of the precipitate (in comparison with that of the polylactide - graft - oligoserine films (Figure S6)) confirmed that degradation occurred, showing the peaks of the copolymer and repeating units of the serine and ethoxy end groups.…”

Section: Results and Discussionmentioning

confidence: 99%

Template-Assisted Enzymatic Synthesis of Oligopeptides from a Polylactide Chain

et al. 2017

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Peptides are often attached to polymer materials, as bioactive components, for the control of interactions between the material and its surrounding proteins and cells. However, synthesizing peptides and attaching them to polymers can be challenging and laborious. Herein, we describe the grafting of oligopeptides to an aliphatic polyester, using a one-step chemo-enzymatic synthesis with papain as the biocatalyst. To enable enzyme-mediated functionalization of the polyester, ethyl hept-6-enoylalaninate (grafter) was synthesized and attached to polylactide chains using thiol-ene click reactions. The oligopeptides were grafted onto the polylactide chains using two different synthetic routes: the grafting from strategy, in which the grafter was attached to the polyester prior to oligopeptide synthesis, or the grafting to strategy, in which oligopeptides were synthesized on the grafter first, then attached to the polymer chain. The final products were analyzed and their structures were confirmed using nuclear magnetic resonance (NMR). The peptide attachment was evaluated using size exclusion chromatography (SEC), contact angle measurement and energy-dispersive X-ray spectroscopy-scanning electron microscopy (EDS-SEM). Furthermore, the mechanistic aspects of the synthesis of the oligopeptides on the grafter were studied using molecular dynamics (MD) simulations. The simulation revealed that hydrogen bonding (between the P1 amide nitrogen of the grafter backbone and the carbonyl oxygen of D158 in the papain) maintain the grafter in a productive conformation to stabilize the transition state of nitrogen inversion, a key step of the biocatalytic mechanism. Apart from being biologically relevant, both experimental and computational results suggest that the designed grafter is a good template for initiating chemo-enzymatic synthesis. The results also showed that the grafting to strategy was more successful compared to the grafting from strategy. Overall, a successful synthesis of predefined peptide functionalized polylactide was prepared, where the oligopeptides were grafted in an easy, time efficient, and environmentally friendly way.

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Section: Results and Discussionmentioning

confidence: 99%

Template-Assisted Enzymatic Synthesis of Oligopeptides from a Polylactide Chain

et al. 2017

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“…The surfactants contain longer carbon chain which leads higher substrate solubility showed higher esterase activity ee value. Organic solvents were often used to increase solubility of substrate because it is reported that esterase activity usually remains in organic solvents (Phytian, 1998;Bornscheuer, 2002). Therefore, organic solvent addition effect of Est-AF was also investigated.…”

Section: (B) (C)mentioning

confidence: 99%

Cloning and characterization of thermostable esterase from Archaeoglobus fulgidus

2008

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Thermostable esterase gene was cloned (Est-AF) from extremophilic microorganisms, Archaeoglobus fulgidus DSM 4304. The protein analysis result showed that Est-AF is monomer with total 247 amino acids and molecular weight of estimated 27.5 kDa. It also showed repeating units G-X-S-X-G (GHSLG) (residues 86 approximately 90) which is reported as active site of known esterases, and the putative catalytic triad composed of Ser88, Asp198 and His226. The esterase activity test with various acyl chain length of rho-nitrophenol resulted that Est-AF showed highest specific activity with rho-nitrophenylbutyrate (pNPC4) and rapidly decrease with rho-nitrophenyl ester contain more than 8 carbon chain. These results represent that cloned enzyme is verified as a carboxylesterase but not a lipase because esterase activity is decreased with rho-nitrophenyl ester contains more than 8 carbon chains but lipase activity does not affected with carbon chain length. Optimum temperature of esterase reaction with rho-nitrophenylbutyrate (pNPC4) was 80 degrees C. When ketoprofen ethyl ester was used as a substrate, activity of Est-AF showed the highest value at 70 degrees C, and 10% of activity still remains after 3 h of incubation at 90 degrees C. This result represents Est-AF has high thermostability with comparison of other esterases that have been reported. However, Est-AF showed low enantioselectivity with ketoprofen ethyl ester. Optimum pH of Est-AF is between pH 7.0 and pH 8.0. Km value of ketoprofen ethyl ester is 1.6 mM and, Vmax is 1.7 micromole/mg protein/min. Est-AF showed similar substrate affinity but slower reaction with ketoprofen ethyl ester compare with esterase from mesophilic strain P. fluorescens.

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“…Numerous of them exhibits atolerance against varied substrate which led to the postulation that they have developed to allow access to sources of carbon or to be incorporated in catabolic pathways. Furthermore, esterases also exhibit extraordinary stereospecificity, therefore in fine-chemicals synthesis this enzyme used asstriking enzymes for the synthesis of optically active pure compounds [1][2][3][4][5][6] . Esterase have another tremendous properties i.e.…”

Section: Introductionmentioning

confidence: 99%

Screening, Isolation and Identification of Thermophilic Esterase Enzyme Isolated from Rhodococcus SP: LKE-021

Singh¹,

Sharma²,

Awasthi³

et al. 2019

J Pure Appl Microbiol

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Rhodococcus sp. LKE-021 from soil samples of the region of Gangotri (10,000 feet of average height) of Uttarakhand Himalayas, India, produced a thermophilic esterase. The physiological and morphological characteristics of the isolated Rhodococcus sp. LKE-021 detected as Gram Positive, rod shape, catalase positive, indole negative, positive to glucose and xylose fermentation test, and can grow on the Nutrient Broth medium. Esterase production confirmed on the basis of spectrophotometric enzyme assay. Taxonomic characteristics Rhodococcus confirmed by 16s rRNA gene sequencing.

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Esterases

Cited by 8 publications

References 154 publications

Template-Assisted Enzymatic Synthesis of Oligopeptides from a Polylactide Chain

Template-Assisted Enzymatic Synthesis of Oligopeptides from a Polylactide Chain

Cloning and characterization of thermostable esterase from Archaeoglobus fulgidus

Screening, Isolation and Identification of Thermophilic Esterase Enzyme Isolated from Rhodococcus SP: LKE-021

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