title: o-Toluoylcholine as substrate for measurement of serum pseudo-cholinesterase activity.
abstract: New synthetic substrates for serum pseudo-cholinesterase activity were compared with the common substrates for the routine assays, with regard to reactivity, specificity and stability; o- and m-toluoylcholine as well as o- and m-toluoyldimethylaminoethanol esters had selective specificities for pseudo-cholinesterase. The last three substrates, however, were unstable in solution at 4 degrees C. On the other hand, o-toluoylcholine could be stored in solution for several days with no appreciable degradation, and it was extremely stable with regard to pH and temperature. No or little hydrolysis of o-toluoylcholine was observed by various enzymes other than pseudo-cholinesterase. The enzymatic method using o-toluoylcholine as substrate was reproducible, and the results correlated well with those obtained using butylthiocholine as substrate and 5,5'-dithiobis-(2-nitrobenzoic acid) as color reagent. In conclusion, o-toluoylcholine is a favorable substrate for the determination of serum pseudo-cholinesterase activity.
mesh_terms: D002091:Butyrylcholinesterase / Q000097:blood* / Q000378:metabolism; D002794:Choline / Q000031:analogs & derivatives*; D002802:Cholinesterases / Q000097:blood*; D003642:Deanol / Q000031:analogs & derivatives; D004983:Ethanolamines; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004983:Ethanolamines; C026356:3-toluoyl choline; C026355:2-toluoyl choline; D003642:Deanol; C026353:2-toluoyl dimethylaminoethanol; C026354:3-toluoyl dimethylaminoethanol; D002091:Butyrylcholinesterase; D002802:Cholinesterases; D002794:Choline