Enzymes cooperating in the hydrolyzing process of benzoylcholines: subcellular and inter-tissue comparison.
Within benzoylcholine biotransformation, butyrylcholinesterase (3.1.1.8, BuChE) appears to be the key enzyme in the hydrolyzing process. Except for BuChE in the process of benzoylcholine hydrolysis, carboxylesterase (3.1.1.1, CE) could play a role in the splitting of the ester bond. The aim of this work was to clarify the interaction between BuChE and CE in the hydrolyzing process of a homologic row of benzolycholines on subcellular and inter-tissue level. Two fractions, microsomes and cytosol of rabbit lung and liver were investigated. Participation of the enzyme activities was determined on the base of kinetic inhibitory studies, using eserine as cholinesterase inhibitor. Despite the fact that in all studied fractions of both organs BuChE and CE were confirmed, only in lung microsomes exclusive BuChE activity in benzoylcholine hydrolyzing process was observed, without substrate specifity. In the other fractions studied interaction of both enzymes were recorded, whereas the benzoylcholine structure played an important role. It seems that, the portion of CE depends predominantly on substrate structure and elevates with bulk of alcoholic part of benzoylcholines. Despite the same enzyme equipment in all tissue fractions studied, the affinity of hydrolyzing enzymes interestingly differs. This might be as a result of distinct subcellular pattern of CE activity localization in lung and liver.
Pauliková
I
I
Department of Cell and Molecular Biology of Drugs, Faculty of Pharmacy, Comenius University, Kalinciakova 8, 832 32 Bratislava, Slovakia. paulikova@fpharm.uniba.sk
Sisková
K
K
D000818:Animals; D001588:Benzoylcholine / Q000378:metabolism*; D002091:Butyrylcholinesterase / Q000378:metabolism*; D043182:Carboxylesterase / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000201:enzymology; D006868:Hydrolysis; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008168:Lung / Q000201:enzymology*; D008297:Male; D008861:Microsomes / Q000201:enzymology; D008862:Microsomes, Liver / Q000201:enzymology; D009928:Organ Specificity; D011817:Rabbits; D013347:Subcellular Fractions / Q000201:enzymology*
D001588:Benzoylcholine; D043182:Carboxylesterase; D002091:Butyrylcholinesterase