Hydrolase Esterase Research Articles

АЦИЛИРОВАНИЕ N-ФОСФОРИЛИРОВАННЫХ ЦИАНОАЦЕТИМИДАТОВ

A method has been developed for the preparation of organophosphorus derivatives of imidic acids, based on the acylation of N-phosphorylated mono-carbon active methylene group. The interaction of sodium derivatives of monoimidates with acid chlorides leads to the formation of the corresponding monoacylated derivatives, for which inhibition of acetyl esterase, esterase hydrolase, cutinase and other enzymes is highly predicted.

Cloning and expression analysis of juvenile hormone epoxide hydrolase-like (EsJHEH-like) from Eriocheir sinensis, and its potential roles in methyl farnesoate metabolism

ABSTRACT The sesquiterpenoid methyl farnesoate (MF), a crustacean equivalent of juvenile hormone (JH III), plays important roles in regulating many physiological processes in crustaceans, especially ovarian development and reproduction. Previous research indicates that degradation of MF in crustaceans is similar to JH III degradation, and involves specific carboxylesterases. Juvenile hormone esterase hydrolase (JHEH) is another important enzyme responsible for JH inactivation in insects. In this study, the full-length cDNA of EsJHEH-like was identified and characterized in Eriocheir sinensis. Sequence analysis showed that EsJHEH-like belongs to the microsomal epoxide hydrolase (mEH) family containing several typical motifs. Quantitative PCR results showed that EsJHEH-like was expressed primarily in the hepatopancreas. During ovarian development, EsJHEH-like mRNA expression in the hepatopancreas was elevated specifically in the early vitellogenic stage, prior to the remarkable rise in haemolymph MF titre reported in previous studies, but no significant changes in the ovary. In addition, EsJHEH-like expression in the hepatopancreas was notably greater than in the ovary at each stage except for previtellogenic oocytes. Furthermore, EsJHEH-like expression in the hepatopancreas was significantly induced in vitro and in vivo, but not in the ovary. Taken together, these results suggest that EsJHEH-like may potentially serve as an MF hydrolase involved in the degradation of MF.

BIOCONVERSION OF LIGNOCELLULOSIC MATERIALS WITH THE CONTRIBUTION OF A FERULOYL ESTERASE HYDROLASE FROM Alternaria tenuissima TO RELEASE CARBOHYDRATES

Feruloyl esterase catalyze the hydrolysis of a wide variety of glycosidic linkages between two or more carbohydrates or between a carbohydrate and a non-carbohydrate moiety. Thereby, they play a role in the initial degradation of lignocelluloses, which may be advantageous for the efficient degradation of the plant cell-wall complex that contains both diverse sugar residues and esterified structures. The contribution of the enzyme AltFAE was purified from Alternaria tenuissima to the conversion of lignocellulosic materials without any chemical pretreatment to release the carbohydrates, was studied. It was determined the activity of feruloyl esterase (AltFAE) production by A. tenuissima in liquid cultures with potential inducing agents sawdust, rice straw, tomato, potato, soybean, and corn starch. At the applied concentrations of soybean (2%), the highest levels ~ 689 U L-1 of enzyme activities were obtained. The disintegrating effect of enzymatic lignocellulose treatment can be significantly improved by using different kinds of hydrolytic and oxidizing enzymes. Synergistic conversion of cane bagasse also resulted in a release of 18.4 mg g-1 total carbohydrates (galactose, glucose, mannose, and xylose) per gram substrate using an “enzyme cocktail” [Cell/Xyl 50 U gds-1, AltFAE 10 U gds-1, and Lac 15 U gds-1] after incubating for 48 hrs at 45oC. The information presented in this paper is helpful to better understand the bioconversion of lignocellulosic materials with the contribution of a feruloyl esterase hydrolase from A. tenuissima to release carbohydrates.

Metabolic changes in tomato fruits and seeds after viral, bacterial and fungal infections

The metabolic changes in tomato fruits and seeds separately infected with cucumber mosaic virus, Pseudomonas syringae pv. tomato or Botrytis cinerea were investigated cytochemically. The changes of peroxidase (E.C. 1.11.1.7) and β-glucosidase (E.C. 3.2.1.21) were investigated biochemically as well. Tomato fruits were involved in the study because of their high economic value. Tomato seeds were investigated since they have been used most extensively as a model system for studying the physiology and biochemistry of seed development. The diseases caused by the pathogens under study are of special importance for yield reduction in tomato. The three pathogens provoked local changes in the activities of enzymes under study that affect the infected pericarp tissues and neighboring seeds. It was established non-specific and specific responses. The non-specific responses of invaded tissues were expressed as a local enhancement of peroxidase activity in both pericarp tissues and seeds as well as a decrease in activities of: i. enzymes taking part in aerobic and anaerobic respiration, ii. hydrolases esterase and acid phosphatase involved in the basic metabolism as well as an enhancement of their activities in neighboring tissues. Furthermore, it was observed an enhancement of α-galactosidase activity in infected area was observed. The specific responses depending on the type of the pathogen consisted in an enhancement of glucose-6-phosphate dehydrogenase activity by virus infection and an increase of β-glucosidase activity by fungal invasion.