Gonadotropin Inhibitors:A Structural Biology Approach To Immunocontraception

描述（由申请方提供）：抗体可干扰促性腺激素活性，破坏生殖过程，从而形成避孕疫苗设计的基础。新的免疫避孕药的分离需要对激素和受体之间的结构相互作用的精确理解。对促性腺激素及其受体的明确认识将有助于设计特异性抑制或增强激素作用的分子。这个建议的目的是检查促性腺激素的结构-功能关系。这将通过两种互补的办法协作完成。首先，是确定新的类似物的激素表现出激动或拮抗性质的结构。早期的研究表明，人绒毛膜促性腺激素（hCG）β β的单链与受体结合而不引发生物活性，以及在体外和体内竞争性抑制天然激素。这种分子的超表达和纯化目前正在印度实验室进行。通过使用先前解出的异源二聚体hCG和促卵泡激素（FSH）的结构，将简化溶液结构。结构溶液分析将使用X射线晶体学以及NMR光谱学。第二种方法利用一组已经可用的单克隆抗体加上本研究期间产生和表征的新抗体来研究受体-受体界面。这些研究将从分泌单克隆抗体的杂交瘤克隆中产生单链片段可变体（ScFv）。我们将探索单链抗体的结构，单独和复杂的激素和突变的单链抗体，这可能会使更高的亲和力的激素。该提案的重点是开发新的生物工具来干扰促性腺激素的作用，同时也探索激素结构的关键方面。印度PI实验室将生产和纯化激素和抗体，而美国PI实验室将确定蛋白质的结构。印度实验室的优势是产生大量纯化和表征的蛋白质，而美国实验室的优势是解决蛋白质结构的能力。因此，这两个实验室的活动相辅相成。印度实验室已经开始努力生产单克隆抗体和单链抗体。这些蛋白质将提供给美国研究人员，他们将试图解决所产生的蛋白质的结构。

DESCRIPTION (provided by applicant): Antibodies can cause interference in gonadotropinic activity disrupting reproductive processes and thereby forming the basis for the design of contraceptive vaccines. The isolation of new immunocontraceptives requires a precise understanding of the structural interactions between hormone and receptor. A definitive insight of the gonadotropins and their receptors will facilitate the design of molecules that will specifically inhibit or enhance hormone action. The objective of this proposal is to examine the structure-function relationship of gonadotropins. This will be accomplished collaboratively using two complementary approaches. First, is to determine the structure of novel analogs of the hormones exhibiting either agonistic or antagonistic properties. Earlier studies have shown that single chain of human chorionic gonadotropin (hCG) beta beta binds to the receptor without eliciting biological activity, as well as competitively inhibiting native hormone both in vitro and in vivo. The hyper-expression and purification of this molecule is currently underway in the Indian laboratory. The solution structures will be simplified by using the previously solved structures of heterodimeric hCG and follicle stimulating hormone (FSH). Structure solution analyses will use X-ray crystallography, as well as NMR spectroscopy. The second approach utilizes a panel of monoclonal antibodies already available plus new antibodies produced and characterized during this study to investigate the hormone-receptor interface. These studies will produce single chain fragment variables (ScFv) from hybridoma clones secreting monoclonal antibodies. We will explore the structure of ScFvs individually and in complex with the hormones and mutations of ScFvs, which may render higher affinity for the hormones. This proposal focuses on developing new biological tools to interfere in the actions of gonadotropins while also probing critical aspects of hormone structure. The laboratory of the Indian PI will produce and purify the hormones and antibodies while the laboratory of the U.S. PI will determine the structure of the proteins. The strength of the Indian laboratory is generating large quantities of purified and characterized protein while the strength of the U.S. laboratory is the ability to solve the structure of the proteins. Thus both laboratories uniquely complement each others activities. The Indian laboratory has already initiated efforts towards production of monoclonal antibodies (MAbs) and ScFvs. These proteins will be supplied to U.S. investigator who will attempt to solve the structure of the proteins produced.