Sadano H, Omura T
Biochem Biophys Res Commun. 1983 Nov 15;116(3):1013-9. doi: 10.1016/s0006-291x(83)80243-5.
Incorporation of newly synthesized heme into microsome-bound cytochrome P-450 in rat liver was not affected by cycloheximide administration to the animals, indicating that the heme incorporation into cytochrome P-450 is not tightly coupled with the synthesis of the apo-cytochrome. When the heme of microsomal cytochrome P-450 had been labeled in vivo with delta-[14C]aminolevulinic acid, and then the animals were treated with phenobarbital (PB) or 3-methylcholanthrene (MC), PB-induced or MC-induced form of cytochrome P-450 was found to contain labeled heme derived from preexistent cytochrome P-450. These observations indicated that the heme of microsome-bound cytochrome P-450 is not tightly associated with the protein portion, and exchanges reversibly between different molecular species of cytochrome P-450 in vivo.
给大鼠施用环己酰亚胺并不影响新合成的血红素掺入大鼠肝脏微粒体结合的细胞色素P - 450，这表明血红素掺入细胞色素P - 450与脱辅基细胞色素的合成并非紧密偶联。当微粒体细胞色素P - 450的血红素在体内用δ-[14C]氨基乙酰丙酸标记后，再用苯巴比妥（PB）或3 - 甲基胆蒽（MC）处理动物，发现PB诱导型或MC诱导型细胞色素P - 450含有源自预先存在的细胞色素P - 450的标记血红素。这些观察结果表明，微粒体结合的细胞色素P - 450的血红素与蛋白质部分并非紧密结合，且在体内不同分子种类的细胞色素P - 450之间可逆地交换。
