REGULATION OF SPERM PROACROSIN CONVERSION TO ACROSIN

在成熟精子中，大多数(如果不是全部)可能的顶体酶(EC 3.4.21.10)作为酶失活的酶原前体存在， 顶体酶原。由于精子需要具有酶活性的顶体酶才能穿透 卵子，顶体酶原必须在精子能够 达到受精的能力。 这项延期提案的主要目标是充分说明 因此，有关其调控的明确信息 可以转化为顶体酶。这将需要一份详细的 顶体酶原的理化性质及其自体蛋白分解 将包括氨基酸序列分析的产品，以便 可以确定精确的键裂解和裂解顺序。这 信息也将被用来定义各种不同的 调控效应对转化过程的影响。进一步深入了解 这些转换效应器和顶体前体酶的关系将是 通过确定它们的绑定参数进行调查，它们对 自聚集与大分子构象变化 伴随着他们的互动。可能的生理学意义 这些对原顶体酶系统的重要调节作用将被确定。 这将包括使用构象特异性抗体来 测定这些成分对顶体酶原三级的影响 细胞水平上的结构。最后，为了获得一个彻底的 了解新生顶体酶原以便对该系统进行定量 并对其转化的调控进行了阐述，将有必要 分离和鉴定新近发现的顶体前体酶前体 附睾精。所有的非酶转化肽都将是 分析了重要的结构-功能关系，因此它们的影响 对原顶体酶转化率的调节可以确定。 这项研究将导致对分子的更完整的理解 受精所需的事件，并最终可能导致 控制它以避孕或提高生育能力的手段 目的。此外，对监管机构有更透彻的理解 这种酶原的机制将增加对 对其他蛋白水解酶系统的可能调节 重要的生物过程。

In mature sperm the majority, if not all, of the potential acrosin (EC 3.4.21.10) is present as an enzymatically inactive zymogen precursor, proacrosin. Since sperm require enzymatically active acrosin to penetrate ova, the proacrosin must be converted into acrosin before the sperm can achieve the capacity to fertilize. The primary goal of this renewal proposal is to sufficiently characterize proacrosin so that definitive information regarding the regulation of its conversion into acrosin can be obtained. This will require a detailed physical-chemical characterization of proacrosin and its autoproteolysis products which will include an amino acid sequence analysis so that the precise bonds cleaved and the order of cleavage can be determined. This information will also be used to define specific influences of various regulatory effectors to the conversion process. Further insight into the relationships of these conversion effectors and proacrosin will be investigated by determining their binding paremeters, their influence on self-aggregation and the macromolecular conformational changes which accompany their interactions. The possible physiological significance of these important regulators on the proacrosin system will be determined. This will include the use of conformationally specific antibodies to measure the influence of these constituents on proacrosin's tertiary structure at the cellular level. Finally, to obtain a thorough understanding of nascent proacrosin so that the system can be quantitated and the regulation of its conversion elucidated, it will be necessary to isolate and characterize proacrosin precursors recently identified in epididymal sperm. All of the non-enzymatic conversion peptides will be analyzed for important structure-function relationships so their influence on the regulation of proacrosin conversion can be determined. This study will result in a more complete understanding of the molecular events required for fertilization and could ultimately lead to possible means of controlling it for either contraceptive or fertility enhancement purposes. In addition, a more thorough comprehension of the regulatory mechanisms of this zymogen will produce increased understanding of the possible regulation of other proteolytic enzyme systems which control many important biological processes.