Yadav Subhash Chandra, Jagannadham Medicherla V
Molecular Biology Unit, Institute of Medical Science, Banaras Hindu University, Varanasi, 221005, India.
Eur Biophys J. 2009 Sep;38(7):981-91. doi: 10.1007/s00249-009-0490-5. Epub 2009 Jun 7.
Spectroscopic, calorimetric, and proteolytic methods were utilized to evaluate the stability of the kinetically stable, differentially glycosylated, dimeric serine protease milin as a function of pH (1.0-11.0), temperature, urea, and GuHCl denaturation in presence of 8 M urea at pH 2.0. The stability of milin remains equivalent to that of native at pH 1.0-11.0. However, negligible and reversible alteration in structure upon temperature transition has been observed at pH 2.0 and with 1.6 M GuHCl. Irreversible and incomplete calorimetric transition with apparent T (m) > 100 degrees C was observed at basic pH (9.0 and 10.0). Urea-induced unfolding at pH 4.0, and at pH 2.0 with GuHCl, in presence of 8 M urea also reveals incomplete unfolding. Milin has been found to exhibit proteolytic resistant in either native or denatured state against various commercial proteases. These results imply that the high conformational stability of milin against various denaturating conditions enable its potential use in protease-based industries.
利用光谱、量热和蛋白水解方法，在pH 2.0且存在8 M尿素的条件下，评估了动力学稳定、糖基化不同的二聚体丝氨酸蛋白酶米林（milin）的稳定性，该稳定性是pH（1.0 - 11.0）、温度、尿素和盐酸胍（GuHCl）变性的函数。在pH 1.0 - 11.0时，米林的稳定性与天然状态相当。然而，在pH 2.0以及1.6 M GuHCl条件下，观察到温度转变时结构发生了可忽略且可逆的变化。在碱性pH（9.0和10.0）下，观察到具有明显高于100℃的T（m）的不可逆且不完全的量热转变。在pH 4.0以及pH 2.0且存在8 M尿素和GuHCl的条件下，尿素诱导的去折叠也显示出不完全去折叠。已发现米林在天然或变性状态下对各种商业蛋白酶均表现出抗蛋白水解能力。这些结果表明，米林对各种变性条件具有高构象稳定性，使其在基于蛋白酶的工业中具有潜在用途。
