Faculty of Arts and Sciences, Department of Chemistry, Yildiz Technical University, Davutpasa Campus, 34210, Esenler, Istanbul, Turkey.
Protein J. 2010 Feb;29(2):120-6. doi: 10.1007/s10930-010-9231-y.
Polycomplex formation of alpha-Amylase from Aspergillus oryzae (TAKA) with polyacrylic acid (PAA) was studied by pH titration, fluorescence, and high performance liquid chromatography (HPLC) methods in water solutions. According to the our results, the complex formation and its solubility were depended on nature of enzyme and the pH of solutions. Both of them correlates isoelectric points (PI). The stability of PAA-amylase complexes was negligibly weak at pH 7 [pH > pI (isoelectric pH)]. Stable water-soluble polycomplexes were formed at pH 5 (pI approximately 4.5) and coexisted with free protein molecules. Insoluble complexes has been observed at pH < 4.5. The frozen storage stabilities of the obtained complexes were also studied by measuring the activities at different pH.
采用 pH 滴定、荧光和高效液相色谱（HPLC）方法研究了米曲霉α-淀粉酶（TAKA）与聚丙烯酸（PAA）在水溶液中的聚络合作用。根据我们的结果，复合物的形成及其溶解度取决于酶的性质和溶液的 pH 值。两者都与等电点（PI）相关。在 pH 7 [pH > pI（等电 pH）] 下，PAA-淀粉酶复合物的稳定性可以忽略不计。在 pH 5（pI 约为 4.5）时形成稳定的水溶性聚络合物，并与游离蛋白质分子共存。在 pH < 4.5 时观察到不溶性复合物。通过在不同 pH 值下测量活性来研究获得的复合物的冷冻储存稳定性。
