Suzuki Y, Murachi T
J Biochem. 1977 Jul;82(1):215-20. doi: 10.1093/oxfordjournals.jbchem.a131672.
The lysate of the glycogen-induced macrophages in rat peritoneal exudate was fractionated by centrifugation and extraction into a water extract, 1 M KCl extract and residue fractions. Approximately 50% of the neutral protease activity toward casein in the lysate was recovered in the KCl extract fraction, which was practically devoid of acid protease, cathepsin D. The pH optimum of the neutral protease toward casein and urea-denatured hemoglobin was pH 8.5. The activity was inhibited strongly by DFP or chymostatin and only partially by HgCl2 or PCMB. Addition of a salt to the reaction medium caused enhancement of the activity with an optimum concentration of 0.25 M: KCl, KBr, KI, NaCl, NaBr, NaI, and MgCl2 were all almost equally effective. When the enzyme preparation was filtered through a column of Sephadex G-75 gel in the presence of 1 M KCl, a larger molecular weight fraction at the void volume was obtained in addition to a smaller molecular weight fraction showing a caseinolytic activity insensitive to KCl concentration. The former was found to have a specific inhibitory effect on the latter activity.
将大鼠腹腔渗出液中糖原诱导的巨噬细胞裂解物通过离心和提取分离成水提取物、1M氯化钾提取物和残渣部分。裂解物中约50%针对酪蛋白的中性蛋白酶活性存在于氯化钾提取物部分，该部分实际上不含酸性蛋白酶组织蛋白酶D。中性蛋白酶对酪蛋白和尿素变性血红蛋白的最适pH为8.5。该活性受到二异丙基氟磷酸酯（DFP）或抑糜酶素的强烈抑制，仅受到氯化汞或对氯汞苯甲酸（PCMB）的部分抑制。向反应介质中添加盐会使活性增强，最佳浓度为0.25M：氯化钾、溴化钾、碘化钾、氯化钠、溴化钠、碘化钠和氯化镁的效果几乎相同。当酶制剂在1M氯化钾存在下通过葡聚糖G - 75凝胶柱过滤时，除了显示出对氯化钾浓度不敏感的酪蛋白分解活性的较小分子量部分外，在空体积处还获得了较大分子量部分。发现前者对后者的活性具有特异性抑制作用。
