Open AccessInhibition of carp liver mitochondrial monoamine oxidase by some commonly-used detergents.
Author(s) -
Hiroyasu Kinemuchi,
Yumi Sunami,
Toshihiko Ueda,
Fumio Morikawa,
Keita Kamijo
Publication year - 1983
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.33.1007
Subject(s) - chemistry , sodium cholate , monoamine oxidase , clorgyline , digitonin , substrate (aquarium) , triton x 100 , tyramine , sodium , non competitive inhibition , chaps , enzyme , chromatography , biochemistry , pulmonary surfactant , biology , organic chemistry , ecology
The inhibitory effects of some detergents commonly used in biochemical research on carp liver mitochondrial monoamine oxidase were examined. Sodium dodecylsulfate, octyl-beta-D-glucopyranoside, sodium cholate and Triton X-100 at relatively low concentrations caused strong dose-dependent inhibition of the activity towards tyramine, but digitonin caused only weak inhibition. Sodium dodecylsulfate, octyl-beta-D-glucopyranoside and sodium cholate caused almost complete inhibition of activity in the concentration ranges tested. The extent of inhibition by Triton X-100 was greater after preincubation at 37 degrees C for 30 min than that without preincubation, but with or without preincubation, the inhibition was not substrate-selective and was not complete at a relatively high concentration (2%) of Triton X-100. Without preincubation, the mode of inhibition by Triton X-100 was competitive and reversible with respect to the oxidations of 5-HT, tyramine and PEA, but after preincubation (37 degrees C for 30 min), it became noncompetitive and irreversible, depending on the concentration of detergent used. These findings suggest that it had different actions on the enzyme depending on preincubation. Triton X-100 also slightly changed enzyme sensitivity towards clorgyline and deprenyl, regardless of the preincubation time or the substrate used. Some possible mechanisms of the inhibitory effect of Triton X-100 are discussed.