Birken S, Chen Y, Gawinowicz M A, Agosto G M, Canfield R E, Hartree A S
Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032.
Endocrinology. 1993 Sep;133(3):985-9. doi: 10.1210/endo.133.3.7689962.
A fragment of the hCG beta-subunit is present in high concentrations in the urine of pregnant women and the urine from individuals with ovarian or other cancers. The utility of immunoreactive measurement of this fragment to monitor therapy of such cancers is compromised, however, because high concentrations of the molecule are also detected in the urine of healthy postmenopausal women. It has been suggested that the latter observations may be due to a cross-reacting human (h) LH beta core fragment, presumably of pituitary origin, but no such fragment had ever been isolated. We have now isolated a hLH beta core fragment from a pituitary tissue extract. Its structure is exactly analogous to that of the hCG beta core fragment. The finding of a discrete hLH beta core fragment in a tissue extract suggests that it may be produced within pituitary tissue, rather than by a peripheral degradation process. We have also found that the same immunoaffinity method used to extract the hLH beta core fragment from the pituitary extract purified several protein fragments from postmenopausal urine, none of which was related to hLH or hCG. The availability of the pituitary hLH beta core fragment may allow development of assays that distinguish it from its hCG analog.
人绒毛膜促性腺激素β亚基的一个片段在孕妇尿液以及患有卵巢癌或其他癌症的个体尿液中浓度很高。然而，通过免疫反应测量该片段来监测此类癌症治疗的效用受到了损害，因为在健康绝经后女性尿液中也检测到了高浓度的该分子。有人提出，后一种观察结果可能是由于一种交叉反应的人促黄体生成素（h）β核心片段，推测起源于垂体，但从未分离出这样的片段。我们现在已经从垂体组织提取物中分离出了一种hLHβ核心片段。其结构与hCGβ核心片段的结构完全类似。在组织提取物中发现一个离散的hLHβ核心片段表明，它可能是在垂体组织内产生的，而不是通过外周降解过程产生的。我们还发现，用于从垂体提取物中提取hLHβ核心片段的相同免疫亲和方法从绝经后尿液中纯化出了几个蛋白质片段，其中没有一个与hLH或hCG相关。垂体hLHβ核心片段的可得性可能有助于开发将其与hCG类似物区分开来的检测方法。
