Incorporation of L-[1-¹⁴C]leucine into protein by liver postmitochondrial supernatant: opposing effects of preincubated nicotinamide-adenine dinucleotide phosphate and 4-dimethylamino-3′-methylazobenzene

Combination of preincubated drug-metabolizing medium containing NADP+ with a cell-free protein-synthesizing system resulted in marked stimulation of incorporation of L-[1-14C]leucine into protein. Addition of 4-dimethylamino-3′-methylazobenzene, present and previously preincubated in the drug-metabolizing medium, decreased this effect.