McGee J O, Langness U, Udenfriend S
Proc Natl Acad Sci U S A. 1971 Jul;68(7):1585-9. doi: 10.1073/pnas.68.7.1585.
A specific antibody to rat collagen proline hydroxylase has been used to measure the amount of "enzyme" protein in cultured mouse fibroblasts (L-929 cells) during normal growth, and under other conditions that cause an increase in enzyme activity. Collagen proline hydroxylase activity per mg of cell protein increased 24-fold as the cells progressed through the logarithmic to the stationary phase of growth, while the cellular concentration of immunologically reactive protein changed only slightly. Similar results were obtained with cells in early log phase in which enzyme activity was stimulated severalfold by cell concentration or lactate treatment without a corresponding change in cellular antigen. It has also been shown that the enzymatically inactive antigen in these fibroblasts competes effectively for antibody-binding sites with partially purified enzyme. It is concluded that early-log-phase fibroblasts contain an inactive form of collagen proline hydroxylase which may be a precursor of the functional enzyme.
一种针对大鼠胶原蛋白脯氨酸羟化酶的特异性抗体已被用于测量正常生长的培养小鼠成纤维细胞（L-929细胞）以及其他导致酶活性增加的条件下“酶”蛋白的含量。随着细胞从对数生长期进入稳定期，每毫克细胞蛋白中的胶原蛋白脯氨酸羟化酶活性增加了24倍，而免疫反应性蛋白的细胞浓度仅略有变化。对数早期阶段的细胞也得到了类似的结果，在这些细胞中，通过细胞浓度或乳酸处理，酶活性被刺激了几倍，而细胞抗原没有相应变化。研究还表明，这些成纤维细胞中无酶活性的抗原能与部分纯化的酶有效竞争抗体结合位点。结论是，对数早期的成纤维细胞含有胶原蛋白脯氨酸羟化酶的无活性形式，它可能是功能性酶的前体。
