Gross M
Biochim Biophys Acta. 1976 Nov 1;447(4):445-59. doi: 10.1016/0005-2787(76)90082-4.
The regulation of protein synthesis by hemin in rabbit reticulocyte lysates is mediated by a hemin-controlled translational repressor protein (HCR) that inhibits polypeptide chain initiation. The effect of this translational inhibitor can be reversed by a high molecular weight protein in the post-ribosomal supernatant fraction. This supernatant factor has been purified approx. 700-fold. It is as effective in reversing the inhibition of protein synthesis due to an early form of HCR (intermediate HCR) as it is in stimulating protein synthesis in the absence of hemin. It is progressively less effective at reversing the inhibition of protein synthesis due to a late from of HCR (irreversible HCR), double-stranded RNA, and oxidized glutathione. The supernatant factor is chromatographically different from the initiation factor IF-MP, isolated from reticulocyte ribosomes, that can also overcome the inhibitory effect of HCR. The supernatant factor does not require hemin for activity, and its action is somewhat suppressed by a level of hemin that is optimal for protein synthesis.
血红素对兔网织红细胞裂解物中蛋白质合成的调节是由一种血红素控制的翻译阻遏蛋白（HCR）介导的，该蛋白抑制多肽链的起始。这种翻译抑制剂的作用可以被核糖体后上清液组分中的一种高分子量蛋白质逆转。这种上清液因子已被纯化约700倍。它在逆转由于早期形式的HCR（中间型HCR）导致的蛋白质合成抑制方面，与在无血红素情况下刺激蛋白质合成一样有效。在逆转由于晚期形式的HCR（不可逆HCR）、双链RNA和氧化型谷胱甘肽导致的蛋白质合成抑制方面，其效果逐渐降低。该上清液因子在色谱上与从网织红细胞核糖体中分离出的起始因子IF-MP不同，IF-MP也能克服HCR的抑制作用。上清液因子的活性不需要血红素，并且其作用在对蛋白质合成而言最佳的血红素水平下会受到一定程度的抑制。
