Protein Z Dependent Proteinase Inhibitor

描述（由申请方提供）：蛋白Z（PZ）是一种维生素K依赖性血浆蛋白，其功能以前未知。我们的工作表明，PZ作为一个辅助因子，以提高（1000倍）抑制凝血因子Xa结合在磷脂表面的一个以前未确定的血浆蛋白称为PZ依赖性蛋白酶抑制剂（ZPI）。ZPI是蛋白酶抑制剂SERPIN超家族的成员，不仅以PZ-、Ca 2 +-和磷脂依赖性方式抑制因子Xa，而且直接抑制凝血因子XIa。本提案的目的是仔细表征负责PZ和ZPI作用的生化机制（目的A），并通过使用人体临床材料（目的B）和小鼠模型（目的C）评估PZ和ZPI产生的凝血调节的生理相关性。目标A下的实验将：1）定义ZPI抑制因子Xa和因子XIa的动力学; 2）表征因子Xa、PZ和ZPI在磷脂表面的相互作用; 3）表征PZ和ZPI之间的相互作用;和4）确定PZ的γ-羧基谷氨酸结构域内的结构和可能影响这些功能特性的ZPI中的氨基末端延伸。在目的B中，将在各种人群/患者组中测量PZ和ZPI，以确定年龄、性别、种族背景和激素治疗对其血浆水平的影响，并评价其与血栓性疾病的潜在关系。在目标C中，PZ和ZPI基因缺失的小鼠和人类疾病的小鼠模型将用于探索这些蛋白质的生理重要性。

DESCRIPTION (provided by applicant): Protein Z (PZ) is a vitamin K-dependent plasma protein whose function was previously unknown. Our work has shown that PZ serves as a cofactor to enhance (1000-fold) the inhibition of coagulation factor Xa bound at a phospholipid surface by a previously unidentified plasma protein called PZ-dependent protease inhibitor (ZPI). ZPI is a member of the SERPIN superfamily of protease inhibitors and not only inhibits factor Xa in a PZ-, Ca2+- and phospholipid-dependent manner, but also directly inhibits coagulation factor XIa. The aims of this proposal are to carefully characterize the biochemical mechanisms responsible for the actions of PZ and ZPI (Aim A) and to assess the physiologic relevance of the regulation of coagulation produced by PZ and ZPI through the use of human clinical materials (Aim B) and mouse models (Aim C). Experiments under Aim A will: 1) Define the kinetics of factor Xa and factor XIa inhibition by ZPI; 2) Characterize the interactions between factor Xa, PZ and ZPI at phospholipid surfaces; 3) Characterize the interaction between PZ and ZPI; and 4) Determine the structures within the gamma-carboxyglutamic acid domain of PZ and the amino-terminal extension in ZPI that may effect these functional properties. In Aim B, PZ and ZPI will be measured in a variety of populations/patient groups to determine the effect of age, gender, ethnic background, and hormonal therapy on their plasma levels and to evaluate their potential relationship to thrombotic disease. In Aim C, PZ and ZPI gene-deleted mice and mouse models of human disease will be used to explore the physiologic importance of these proteins.