Resistance in a dual malathionand permethrin-resistant head louse strain (BR-HL) was studied. BR-HL was 3.6and 3.7-fold more resistant to malathion and permethrin, respectively, compared to insecticide-susceptible EC-HL. S,S,S-Tributylphosphorotrithioate synergized malathion toxicity by 2.1-fold but not permethrin toxicity in BR-HL. Piperonyl butoxide did not synergize malathion or permethrin t...

In this study, esterase isozyme polymorphisms in Boreal-Tertiary origin relict endemic L. orientalis populations were investigated. Four populations located in the Southern and the Southwestern regions of Turkey were screened. Two of these populations (Fethiye-Günlüklü and Fethiye-İnlice) belong to subspecies L. orientalis Mill.var. orientalis. The other two (Muğla-Köyceğiz and Antalya-Gebiz) b...

One hundred and seventy-one genes encoding potential esterases from 11 bacterial genomes were cloned and overexpressed in Escherichia coli; 74 of the clones produced soluble proteins. All 74 soluble proteins were purified and screened for esterase activity; 36 proteins showed carboxyl esterase activity on short-chain esters, 17 demonstrated arylesterase activity, while 38 proteins did not exhib...

LTHOUGH the esterases can be separated in column chromotography or by A the use of paper or agar gel electrophoresis, the introduction of starch gel and acrylamide gel systems has made it possible to conveniently sort out and quantitatively measure the multiple molecular forms (isozymes) of esterases. In recent years evidence has been accumulating which indicates genetic control over these isoz...

Biochemical mechanisms of malathion resistance were investigated in a malathion-resistant strain of the parasitoid Habrobracon hebetor Say collected from a farm storage in Kansas. General esterase activities were significantly lower in the resistant strain compared with those in a susceptible strain. However, no significant differences were found in activities of malathion specific carboxyleste...

The greenbug aphid, Schizaphis graminum (Rondani) has developed resistance to organophosphorus insecticides by the over-production of esterases that have been classified as Type I and Type II. The first twenty N-terminal amino acids of the Type I esterase were determined and used to design an oligonucleotide, which in conjunction with an active site primer derived from conserved sequences of ot...

INTRODUCTION Electrophoretic techniques by which mixtures of isoenzymes, and homologous proteins generally, may be resolved have become valuable tools in developmental biology. They make possible the study of development at the molecular level, in the sense that the differentiation of protein patterns underlies ontogenetic changes and tissue differences. The greater successes of this approach h...

Brivanib alaninate, the L-alanine ester prodrug of brivanib, is currently being developed as an anticancer agent. In humans, brivanib alaninate is rapidly hydrolyzed to brivanib. Prominent biotransformation pathways of brivanib included oxidation and direct sulfate conjugation. A series of in vitro studies were conducted to identify the human esterases involved in the prodrug hydrolysis and to ...

Bacillus subtilis NRRL 365 produced high extracellular carboxyl esterase activity in submerged culture media containing wheat bran, corn steep liquor, and salts. Supplementation of this medium with glucose reduced esterase activity to 37% of that in the unsupplemented control. Esterase activity was purified by ammonium sulfate fractionation, DEAE-Sephadex A-50 ion-exchange chromatography with s...