The methionine analog, L-ethionine, induces morphological and biochemical changes in cultured HL-60 cells which are indicative of myeloid maturation. After 3 to 5 days of growth in the presence of L-ethionine, the majority of cells have enhanced phagocytic ability. The percentage of cells in the culture which bear complement receptors and which can respond to 12-O-tetradecanoylphorbol-13-acetat...

alpha-naphthyl acetate esterase (ANAE) activity has been investigated in leukaemic cells from peripheral blood in a typical small-cell Sézary syndrome (SS) case in which cerebriform mononuclear cells failed to form E rosettes. The 'dot-like' ANAE positivity found in the majority of these neoplastic cells strongly supports a T-cell origin. In addition, a non-monocytic, non-B-cell nature of Sézar...

The structure of PFE, an aryl esterase from Pseudomonas fluorescens, has been solved to a resolution of 1.8 A by X-ray diffraction and shows a characteristic alpha/beta-hydrolase fold. In addition to catalyzing the hydrolysis of esters in vitro, PFE also shows low bromoperoxidase activity. PFE shows highest structural similarity, including the active-site environment, to a family of non-heme ba...

Simwiary. \lMultiple forms of hydIrolytic enzymes Nvere deemonstrated in extracts of healthy tean leaves (Phla(scoluts vtulgaris L.) anld bean leaves infecte(d with the halo blight organism [Pseudoiiioiias phascolicola (Burkh.) Dowson] by polyacrylamide (lisc elecrophoresis. Bean leaves conitainiedl up to 4 acid l)hosphatase bands, 9 esterase banlds active towards a-niaphthyl acetate, alnd 7 es...

BACKGROUND Lactofen, a member of the diphenylether herbicides, has high activity and is commonly used to control broadleaf weeds. As a post-emergent herbicide, it is directly released to the environment, and easily caused the pollution. This herbicide is degraded in soil mainly by microbial activity, but the functional enzyme involved in the biodegradation of lactofen is still not clear now. ...

Carbohydrate-active enzymes (CAZymes) regulate the synthesis, degradation, and modification of the poly—and oligosaccharides in all three kingdoms of life. A novel carbohydrate acetylesterase from Sinorhizobium meliloti, designated SmAcE1, was identified, characterized, and crystallized. This SmAcE1 is classified into the carbohydrate esterase family 3 (CE3) based on the sequence alignments wit...

Two or possibly three equivalents of N-bromoacetylacetazolamide interact with two histidine residues located in the active site region of human carbonic anhydrase B. The most rapid reaction occurs at the l-nitrogen of a histidine residue and this is followed by a slower alkylation of the 3-nitrogen of the same histidine and the 3-nitrogen of a second histidine. From a reaction mixture of N-brom...

The inhibition kinetics of dichlorvos on carboxylesterase and acetylcholinesterase (AChE) activity extracted from Liposcelis bostrychophila and L. entomophila (Psocoptera: Liposcelididae) were compared. The results showed that L. entomophila had significantly greater specific activity of carboxylesterase than L. bostrychophila (0.045 versus 0.012 micromoles/mg/min). Moreover, the carboxylextera...

Phosphotriesterase from Pseudomonas diminuta (PTE) is an extremely efficient metalloenzyme that hydrolyses a variety of compounds including organophosphorus nerve agents. Study of PTE has been hampered by difficulties with efficient expression of the recombinant form of this highly interesting and potentially useful enzyme. We identified a low-level esterolytic activity of PTE and then screened...