Inhibition of human plasma and serum butyrylcholinesterase (EC 3.1.1.8) by alpha-chaconine and alpha-solanine.
The purpose of these experiments was to determine the reversibility of alpha-chaconine and alpha-solanine inhibition of human plasma butyrylcholinesterase (BuChE). For the substrate alpha-naphthylacetate, optimal assay conditions were 0.50 M sodium phosphate buffer and a substrate concentration of 3-5 x 10(-4) M. Dibucaine (1 x 10(-5) M) indicated the usual phenotype for all subjects; alpha-chaconine and alpha-solanine at 2.88 x 10(-6) M inhibited BuChE about 70 and 50%, respectively. One- and 24-hr incubations at 1 x 10(-5) M with alpha-chaconine, alpha-solanine, paraoxon, eserine, and ethanol yielded reversible inhibition with dilution except for paraoxon. Twenty-four-hour dialyses of incubations showed no inhibition except for paraoxon. PAGE enzyme activity gels of 1- and 24-hr incubations also showed no inhibition except for paraoxon. alpha-Chaconine and alpha-solanine are reversible inhibitors of human butyrylcholinesterase. At estimated tissue levels, alpha-chaconine, alpha-solanine, and solanidine inhibited BuChE 10-86%. In assays which combined alpha-chaconine, alpha-solanine, and solanidine, inhibition of BuChE was less than additive. No inhibition of albumin alpha-naphthylacetate esterase (an arylesterase) was noted with any inhibitor. The importance of these data to adverse toxicological effects of potato alkaloids is discussed.
Nigg
H N
HN
University of Florida, IFAS, Citrus Research and Education Center, Lake Alfred 33850, USA.
Ramos
L E
LE
Graham
E M
EM
Sterling
J
J
Brown
S
S
Cornell
J A
JA
D002091:Butyrylcholinesterase / Q000097:blood*; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D010261:Paraoxon / Q000494:pharmacology; D012992:Solanine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D013379:Substrate Specificity
D002800:Cholinesterase Inhibitors; D012992:Solanine; C011860:alpha-chaconine; D002091:Butyrylcholinesterase; D010261:Paraoxon