Cholinesterases conjugated

Different technologies and methods based on cholinesterases have been developed for low cost and fast detection of anti-ChEs with high sensitivity, accuracy and storage stability (Periasamy et al., 2009). These include a novel development of cholinesterases conjugated to nanomaterial-based sensors. In such systems, the cholinesterases are conjugated to nanomaterials such as carbon nanotubes (CNTs), metallic nanoparticles (NPs), or semiconductor NPs, which enable the use of their unique properties, in the nano regime, to achieve the requirements from satisfactory sensors. 

Cholinesterase catalysis and inhibition mechanisms involve formation of reversible complexes and covalent conjugates 197... 

These examples show that OPs can bind covalently to albumin under physiological conditions, and that the resultant adducts are relatively stable. OP-albumin adducts could therefore be useful as biomarkers of OP exposure. In addition, unlike cholinesterases, the soman-albumin conjugate does not age (Li et al, 2008a), making it possible to discriminate between sarin and soman exposure. OP-albumin adducts have not yet been reported in humans exposed to OPs. 

Hetnarski, B. and O Brien, R.D. (1973). Charge Transfer in Cholinesterase Inhibition. Role of the Conjugation Between Carbamyl and Aryl Groups of Aromatic Carbamates. Biochemistry, 12, 3883-3887. 

Kovarik Z, Radic Z, Berman HA et al. (2004). Mutant cholinesterases possessing enhanced capacity for reactivation of their phospho-nylated conjugates. Biochemistry, 43, 3222-3229. 

A detailed quantitative study of harmlne metabolism in man and rats was reported (0.5 mg/kg i.v.). Harmol sulfate was the primary conjugate in rats and harmol glucuronlde excretion predominated in man. Harmlne (i.v.) in cats, rats and humans induced bradycardia and hypotension and the effects of acetylcholine and epinephrine were potentiated due to inhibition of cholinesterase and MAO respectively. The effect of harmlne on serotonin- C metabolism was reported. ... 

M. expansa was cytosolic and conjugated CDNB but not bromobenzene or chlorobenzene (Douch and Buchanan 1978). Similarly, glutathione-S-transferase activity in H. contortus was observed only with CDNB as substrate and not with DCNB or l,2-epoxy-3-(p-nitrophenoxy)propane (Kawalek et al. 1984). Neither M. expansa not A. suum produced glucuronides with 4-nitrophenol, 2-aminophenol or 4-methylumbelliferone (Douch and Blair 1975), or possessed measurable DDT-dehydrochlorinase activity (Douch and Buchanan 1978). Various specific (cholinesterase) and non-specific esterases have been detected in trematodes, e.g. using a-naphthyl acetate as substrate, in A laria marcianae (Dickinson and Johnson 1978) and Schistosoma mansoni and Schistosoma haematobium (Coles 1970). 

Cholinesterases were conjugated by different bioconjugation techniques to colloidal NPs of different compositions, dimensions, and surface coating allowing fine tuning of the NPs to the desired application (Figure 52.3A Waiskopf et al., 2011, 2013). Cholinesterases were also conjugated to NPs deposited on electrodes. 

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