Wintroub B U, Schechter N B, Lazarus G S, Kaempfer C E, Schwartz L B
J Invest Dermatol. 1984 Nov;83(5):336-9. doi: 10.1111/1523-1747.ep12264144.
Human skin chymotrypsin-like proteinase, human neutrophil cathepsin G, rat mast cell chymase, and rat salivary gland tonin are cell-derived serine proteinases of similar size with specificity for amino acids of aromatic residues. Each enzyme was examined for its ability to convert angiotension I to angiotensin II and to cleave a panel of synthetic substrates. Skin chymotryptic proteinase, cathepsin G, and tonin cleaved the phe8-his9 bond of angiotensin I and converted angiotensin I to angiotensin II without further degradation. In contrast, chymase formed relatively small amounts of angiotensin II because it preferentially cleaved the tyr4-ile5 bond of angiotensin I. The rank order of angiotensin I converting activity was skin chymotryptic proteinase greater than tonin greater than cathepsin G greater than chymase. The Km and Kcat for angiotensin I conversion by the human skin enzyme were 6.6 X 10(-5) M and 50 s-1, respectively. The angiotensin I converting activity of human skin chymotryptic proteinase is equal to or greater than the peptidyl dicarboxypeptidase angiotensin-converting enzyme. Substrate specificities of each enzyme were further distinguished by use of benzoyl-L-tyrosine ethyl ester. A limited immunologic characterization of each enzyme was performed with monospecific goat antiserum to cathepsin G and chymase by Ochterlony gel diffusion. Each antiserum gave a precipitin line against its respective immunogen without evidence of cross-reactivity against the other enzymes. Human skin chymotryptic proteinase, cathepsin G, and tonin provide unique pathways for the generation of angiotensin II in tissue and may be of significance in regulation of biologic processes of the tissue microenvironment. The kinetic constants of the human skin chymotryptic proteinase for angiotensin I conversion, are consistent with the potential to carry out a reaction of physiologic importance.
人皮肤类胰凝乳蛋白酶样蛋白酶、人中性粒细胞组织蛋白酶G、大鼠肥大细胞糜酶和大鼠唾液腺血管紧张肽原酶是细胞衍生的丝氨酸蛋白酶，大小相似，对芳香族氨基酸残基具有特异性。研究了每种酶将血管紧张素I转化为血管紧张素II以及切割一组合成底物的能力。皮肤胰凝乳蛋白酶样蛋白酶、组织蛋白酶G和血管紧张肽原酶切割血管紧张素I的苯丙氨酸8-组氨酸9键，将血管紧张素I转化为血管紧张素II，且无进一步降解。相比之下，糜酶形成的血管紧张素II量相对较少，因为它优先切割血管紧张素I的酪氨酸4-异亮氨酸5键。血管紧张素I转化活性的排序为：皮肤胰凝乳蛋白酶样蛋白酶＞血管紧张肽原酶＞组织蛋白酶G＞糜酶。人皮肤酶转化血管紧张素I的Km和Kcat分别为6.6×10⁻⁵M和50 s⁻¹。人皮肤胰凝乳蛋白酶样蛋白酶的血管紧张素I转化活性等于或大于肽基二肽羧肽酶血管紧张素转换酶。通过使用苯甲酰-L-酪氨酸乙酯进一步区分了每种酶的底物特异性。用针对组织蛋白酶G和糜酶的单特异性山羊抗血清通过奥克特洛尼凝胶扩散对每种酶进行了有限的免疫学鉴定。每种抗血清均针对其各自的免疫原产生沉淀线，没有针对其他酶的交叉反应证据。人皮肤胰凝乳蛋白酶样蛋白酶、组织蛋白酶G和血管紧张肽原酶为组织中血管紧张素II的生成提供了独特途径，可能在组织微环境的生物学过程调节中具有重要意义。人皮肤胰凝乳蛋白酶样蛋白酶转化血管紧张素I的动力学常数与进行具有生理重要性反应的潜力一致。
