Antibodies raised against esterase-4 and esterase-5 from Drosophila mojavensis were coupled to Protein A-Sepharose CL-4B to prepare high-efficiency immunomatrices used for their purification. Final purification was achieved by anion-exchange h.p.l.c., in the case of esterase-5 followed by gel-filtration h.p.l.c. The resultant esterase preparations were homogeneous, as judged by gel-filtration h...

Prototrophic hybrids formed from an adenine-requiring Chinese hamster cell and human fibroblasts uniformly display new esterase activity that differs from that of either parental cell in electrophoretic mobility and substrate specificity. The hybrids that grew in the selective medium and possessed the new esterase activity had a single extra chromosome that resembled a B-group human chromosome....

Cholinesterase inhibitors are the only approved drug treatment for patients with mild to moderately severe Alzheimer's disease. Interestingly, the clinical potency of these drugs does not correlate well with their activity as cholinesterase inhibitors, nor is their action as short lived as would be expected from purely symptomatic treatment. A few cholinesterase inhibitors, including galantamin...

The enzyme, esterase B2, involved in insecticide resistance has been purified and characterized from the mosquito Culex quinquefasciatus. The monomeric enzyme has an M(r) of 62000 and a pI of 5.0. This enzyme is compared with the esterase A2 previously characterized [Ketterman, Jayawardena and Hemingway (1992) Biochem. J. 287, 355-360]. The kinetic constants for interaction with several insecti...

Methicillin-sensitive and methicillin-resistant strains of Staphylococcus aureus from diverse geographic origins were analysed by polyacrylamide-agarose gel electrophoresis for esterase polymorphism. Three kinds of esterase bands, designated A, B and C, were defined by their ranges of activity toward five synthetic substrates and their resistance to di-isopropyl fluorophosphate. There were five...

The specificity of the amidase and kininogenase methods for determining rat urinary kallikrein was studied. Male and female rat urine was employed. Esterase A1, A2 and kallikrein were separated by DEAE-Sephadex A-50 chromatography. Esterase A1 showed no amidase activity towards the substrate H-D-Val-Leu-Arg-p-nitroanilide. In contrast, esterase A2 and kallikrein attacked the substrate, and the ...

Field collected An. stephensi larvae were colonized in the laboratory for 15 generations and acclimatized. An isofemale line was raised from this colony and the larvae were subjected to continuous deltamethrin selection pressure. LC50 and LC90 values were calculated at every generation. The values indicated that at the end of seventh generation the larvae have developed 87 fold tolerance in ter...

The formation of C'1 esterase from C'1, the first component of complement, may be brought about by the action of plasmin or trypsin upon C'1s, a subcomponent of C'1. These enzymes also decrease the esterolytic activity of C'1 esterase. The formation of C'1 esterase was demonstrated by measuring the appearance of an agent or agents with esterolytic properties and the capacity to inactivate C'2 a...

Resistance to organophosphates in Culex mosquitoes is typically associated with increased activity of non-specific esterases. The commonest phenotype involves two elevated esterases, A2 and B2, while some strains have elevation of esterase B1 alone. Overexpression of the two B esterase electromorphs is due to gene amplification. Full-length cDNAs coding for amplified esterase B genes from a res...

Specific esterase activity, a property generally ascribed to cells of granulocytic origin, was found in abnormal erythroid precursors obtained from the bone marrows of six patients with untreated erythroleukemia. These erythroblasts also showed nonspecific esterase activity. Neither specific nor nonspecific esterase activity was detected in erythroid precursors obtained from the bone marrows of...