Mono[14C]acetyl-chymotrypsin was prepared by treating alpha-chymotrypsin with a 10-fold molar excess of p-nitrophenyl[14C]acetate at pH 5, and the acetylated enzyme was isolated free of excess reagents by gel filtration. Deacetylation at pH 6.0 was followed by observing the decrease in acid-precipitable radioactivity and provided a first-order rate constant of 0.02 +/- 0.008 min-1. Reactivation...

Granulocytes from the peripheral blood of normal subjects and a patient with hereditary myeloperoxidase deficiency were homogenized in 0.34 M sucrose. A granule-rich fraction, prepared by sedimentation at 27,000 x g for 20 min, contained components that killed C. parapsilosis in vitro. These were extractable with 0.01 M citric acid and were shown by micropreparative polyacrylamide electrophores...

Purified human milk lipoamidase was digested with endoproteinase Lys-C and the digested peptides were subjected to gasphase microsequence analysis. The sequencing of three isolated peptides of human milk lipoamidase revealed the identity of this protein with human milk bile salt-stimulated lipase (pancreatic cholesterol esterase). The identity of the cholesterol esterase with lipoamidase was co...

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...

I applied the fluorescein diacetate (FDA) hydrolysis technique as a rapid and sensitive estimator of total esterase activity in stream sediment biofilms. I investigated the effects of temperature, pH and incubation time and optimized the assay for low blanks and high fluorescein extraction. The FDA procedure was precise (c.v. = 4.15%) and could detect 10 nM fluorescein. Spatial patterns of este...

BACKGROUND Microorganisms are the most proficient decomposers in nature, using secreted enzymes in the hydrolysis of lignocellulose. As such, they present the most abundant source for discovery of new enzymes. Acremonium alcalophilum is the only known cellulolytic fungus that thrives in alkaline conditions and can be cultured readily in the laboratory. Its optimal conditions for growth are 30°C...

Several properties of the cholinesterase from Phaseolus aureus Roxb. and of pectin (methyl) esterases from both Phaseolus aureus and Lycopersicon esculentum (L.) Mill. are contrasted. Cholinesterase activity is inhibited by all of the concentrations of NaCl tested, from 0.05 m to 0.9 m, a property which differs sharply from published data pertaining to pectin esterase. Although crude preparatio...