Microsomal cytochromes b5 and P450 during induction of aryl hydrocarbon hydroxylase activity in mammalian cell culture.

摘要: Abstract 1. Aryl hydrocarbon hydroxylase is a microsomal enzyme system which inducible by polycyclic hydrocarbons in hamster fetal cells grown culture. While the specific activity of increases more than 20-fold 21 hours, there are 80%, 40%, and 100% total heme, cytochrome b5, CO-binding pigment, respectively, membranes these cells. 2. There no significant difference between extinction coefficient for reduced hemoprotein-CO complex from control that benz[a]anthracenetreated 3. A cytochrome, absorbs maximally at about 446 nm, closely associated with aryl appearance (a) dependent upon protein synthesis (b) not intracellular presence benz[a]anthracene per se. 4. Increases oxygenase concentrations, observed fractions exposed to inducer, similar magnitude those found liver when pregnant rat treated benz[a]anthracene. 5. The P450 easily converted P420 experimental manipulations such as vigorous homogenization incubation vitro KSCN, compared pigment benz[a]anthracene-treated