Structure-function analysis of the plasma protein fetuin-B

血浆蛋白胎球蛋白-B是卵母细胞受精所必需的。胎球蛋白B是一种有效的蛋白酶抑制剂，可防止卵母细胞成熟过程中卵蛋白的过早活性。因此，胎球蛋白B维持卵母细胞的生育力。在没有抑制剂的情况下，奥伐他汀切割透明质酸蛋白ZP 2，从而介导卵母细胞细胞外基质的主要结构变化。这个过程通常被称为透明“硬化”。透明质膜硬化后，精子不能结合、穿透卵母细胞并使其受精。胎球蛋白B缺陷的雌性小鼠完全不育，因为它们的卵母细胞具有过早硬化的透明质。在这项研究中，我们计划获得胎球蛋白-B（抑制剂）和ovastacin（蛋白酶）之间特异性相互作用的机制知识。我们问胎球蛋白-B和ovastacin之间的相互作用是否仅在受精前或在早期胚胎发育和孵化期间重要。我们将确定的结构特征，这是必不可少的抑制ovastacin。这些知识将有助于开发创新的非激素避孕疗法，也将有助于为特发性不孕症妇女制定治疗策略。大约15%的夫妇对孩子的渴望没有得到满足。为了优化辅助生殖治疗，非常需要用于卵母细胞质量控制的新参数。我们将研究纳米压痕技术作为一种快速、无偏、非破坏性的卵母细胞质量控制方法。

The plasma protein fetuin-B is essential for the fertilization of oocytes. Fetuin-B is a potent inhibitor of the proteinase ovastacin preventing premature activity of ovastacin during oocyte maturation. Thus fetuin-B maintains the fertility of the oocyte. In the absence of the inhibitor ovastacin cleaves zona pellucida protein ZP2 thus mediating major structural changes of the oocyte extracellular matrix. This process is generally known as zona pellucida “hardening”. Following zona pellucida hardening sperm is unable to bind, penetrated and fertilize the oocyte. Fetuin-B deficient female mice are completely infertile, because their oocytes have a prematurely hardened zona pellucida. In this research proposal we plan to gain mechanistic knowledge about the specific interaction between fetuin-B (inhibitor) and ovastacin (proteinase). We ask if the interaction between fetuin-B and ovastacin is only important before fertilization or also during the early embryo development and hatching. We will determine structural features, which are essential for the inhibition of ovastacin. The knowledge will aid the development of innovative non-hormonal contraceptive therapies, and will also help do develop therapeutic strategies for women with idiopathic infertility. About 15% of couples have an unfulfilled desire for a child. To optimize the assisted reproductive therapies, novel parameters for oocyte quality control are highly desirable. We will study nanoindentation of oocyte as a quick, unbiased and non-destructive method for oocyte quality control.