ENAMEL SECRETORY MATRIX PROTEASE

分泌过程中沉积在牙釉质中的大部分基质蛋白 在釉质的分泌后发育过程中失去了阶段。这种蛋白质 在损失之前，基质的分子量显著减少 蛋白质。据推测，这种分子量的减少是 由一种与基质一起分泌的蛋白水解酶完成。一个 发育中牙釉质中丝氨酸蛋白酶活性的研究已有报道。 在初步研究中，我们分离了一种蛋白水解酶 牛胚胎分泌性釉质。这种酶只代表一小部分 在总的基质蛋白中，它的活性非常低，直到 通过亲和层析从大块蛋白质中分离出来。这个 钙激活的酶。这个项目的目的是进一步描述 并研究其对釉质基质形成的影响。 具体目标如下：(1)丝氨酸蛋白酶的提纯和纯化 用模型确定该酶裂解的键的特异性 底物和釉质基质；(2)测定酶是否 水解釉原蛋白和/或釉质蛋白；(3)确定 酶以蛋白酶或抑制物的形式分泌；以及(4) 确定该酶的抑制剂是否抑制体外损失 由先前合成的基质蛋白制成的釉质。

Most of the matrix protein that is deposited in enamel during the secretory stage is lost during the postsecretory development of enamel. This protein loss is preceded by marked decreases in the molecular weights of the matrix proteins. It has been postulated that this molecular weight decrease is accomplished by a proteolytic enzyme that is secreted with the matrix. A serine protease activity in developing enamel has been reported. In preliminary studies, we have isolated a proteolytic enzyme from embryonic bovine secretory enamel. This enzyme represents a small fraction of the total matrix protein, and it has very low activity until it is separated from the bulk of the protein by affinity chromatography. The enzyme calcium-activated. This project is designed to further characterize this enzyme and to study its effect on developing enamel matrix. The specific aims are as follows: (1) to purify the serine protease and to determine the specificity of bonds cleaved by this enzyme using model substrates and enamel matrix; (2) to determine whether the enzyme hydrolyzes amelogenins, enamelins, or both; (3) to determine whether the enzyme is secreted as a protenzyme or with an inhibitor; and (4) to determine whether inhibitors of the enzyme inhibit the in vitro loss from enamel of previously synthesized matrix proteins.