Acetylcholinesterases classification

Usually several categories of classification are appropriate. For example, parathion is an insecticide that is produced industrially, to which exposure may occur as a mist from spray, and that binds to the acetylcholinesterase enzyme, affecting function of the nervous system. 

Currently, it is not possible to accurately transform data gathered from molecular markers to predict effects at the population and community levels of organization. Certainly, behavioral alterations caused by acetylcholinesterase inhibitors may cause an increase in predation or increase the tendency of a parent to abandon a brood, but the long-term populational effects are difficult to estimate. In the estimation and classification of potential effects, it may be the pattern of indicators that is more important than the simple occurrence of one that is important. 

Over 80 different (3-lactamases are now known. One classification is a system that divides the enzymes into three classes A, B, and C. Classes A and C are active-site serine enzymes. The serine residue in class A enzymes is at position 70. This class contains four major (3-lactamases 749/C (from B. licheniformis), PCI (from S. aureus), 569/H P-lactamase I (from B. cereus), and PBR322 and RTEM (from E. coli). As with other serine-type hydrolytic enzymes (acetylcholinesterase, trypsin), the mechanism of action requires initial formation of an acylated enzyme, in this case acylation of ser-70 followed by hydrolysis of the derivative to regenerate the enzyme ... 

A. Classification and Prototypes The three major classes of insecticides are the chlorinated hydrocarbons (DDT and its analogs), acetylcholinesterase inhibitors (carbamates, organophos-phates), and the botanical agents (nicotine, rotenone, pyrethrum alkaloids). 

Methods have been published that allow the classification of two types of esterases, the carboxylic ester hydrolases (CEHs) and the phosphoric triester hydrolases (PTEHs) (Anspaugh and Roe, 2004). The CEHs contain the B-esterases, which are inhibited by organophosphates. B-esierases include many other esterases, such as CarbE, acetylcholinesterase (AChE), cholinesterases (ChE), aryleslerases, sterol esterases, insect juvenile hormone esterases, aixl others. The determination of A-esterases uses a protocol for the detection of PTEHs. The PTEH assay allows for the identification of two subclasses of esterases, the A-esterase (known as aiyldialkylphos-phatase) and ditsopropyl fluorophosphatase. Both these enzymes metabolize OP compounds. 

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