Electrophoretic and irreversible heterogeneity and age-related change of enzyme molecule

从Aspergillus Sojae中分离的丝氨酸蛋白酶似乎在pH值4.0和7.8中是同源的，并展示了一种分化模式，显示了一个主要波段和四个次要波段的存在，在pH值9.4中注意到的盘凝胶电泳。这些被用于治疗阴极、九月和九月<I><II>，<III><IV><V>当血管紧张素在pH值7.5和30 ° C的多种形式的丝氨酸蛋白酶中被测定，每个形式都被水解为&lt;Tyr^4&gt; - &lt;Ile^5&gt;键。增加流动性从9月到9月只影响价值的因素<IV><II><K_m>，但在催化速率&lt;k_（cat）&gt;中导致了一个惊人的增加。当&lt;k_（cat）&gt;的值<K_m>被发现反对丝氨酸蛋白质流动性的转向该方法时，曲线显示与年龄相关的变化，就像生长曲线一样。最大值&lt;k_（猫）&gt; /<K_m>值显示为9月<II>，<V>当9月在三氯HCl缓冲液中孵化为pH值为8.0和30 ° C，9月观察<IV>到SDS凝胶电泳。类似的分子转化是在9月和9月的分子物种<IV>孵化下观察的<III>，相应地。类似的分子权重值在SDS凝胶电泳中找到了这些多重形式。这是如何，重要的是要学习SDS凝胶的电泳在9月显示一个<I>主要带，具有36 K和两个低分子重量分数的19 K和17 K，在pH值8.0溶液中孵化为30 ° C。这些多种形式有相同的N-和C-终极氨基酸替代方案。而且没有明显的差异，只有轻微的适应性变化被观察到，这是第一份关于系列蛋白质类别的电活性的报告，该报告显示了与年龄相关的变化。

A serine proteinase isolated from Aspergillus sojae seemed to be homogeneous by free boundary electrophoresis at pH 4.0 and 7.8, and the sedimentation pattern showed it to be monodisperse.However, the presence of a major band and four minor bands was noted on disc gel electrophoresis at pH 9.4. These were termed in order of their decreasing mobility towards the cathode, Sep <I> , Sep <II> , Sep <III> , Sep <IV> and Sep <V> .When angiotensin was digested with the multiple forms of serine proteinase at pH 7.5 and 30゜C, each form hydrolyzed the <Tyr^4> - <Ile^5> bond. Increasing the mobility toward the cathod from Sep <IV> to Sep <II> affects the <K_m> values only slightly, but caused a remarkable increase in the catalytic rate <k_(cat)> . When the value of <k_(cat)> / <K_m> are plotted against electrophoretic mobility of the serine proteinase toward the cathod, the curve shows age-related change like a growth curve. The maximum <k_(cat)> / <K_m> value is shown with Sep <II> .When Sep <V> was incubated in Tris-HCl buffer at pH 8.0 and 30゜C for one night, Sep <IV> was observed on SDS gel electrophoresis. Similar molecular conversion was observed with the incubation of the molecular species Sep <IV> and Sep <III> , respectively.Similar molecular weight values of these multiple forms were found on SDS gel electrophoresis. It was, however, important to learn that the SDS gel electrophoresis of Sep <I> shows a major band with molecular weight of 36 K and two lower molecular weight fraction of 19 K and 17 K when incubated at 30゜C in a pH 8.0 solution. These multiple forms have the same N- and C- terminal amino acid residues. And no significant differences and only minor conformational changes were observed.This is the first report that the catalytic activities of electrophoretic species of the serine proteinases shows age-related change.