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用ＦＴＩＲ研究了不同浓度ＮａＣｌ溶液中α－辅肌动蛋白二级结构的变化。实验结果发现，在不同ＮａＣｌ浓度下，α－辅肌动蛋白至少具有三种不同的构象：低盐（３０－９０ｍｍｏｌ／ＬＮａＣｌ），中盐（１５０ｍｍｏｌ／Ｌ－２５０ｍｍｏｌ／ＬＮａＣｌ）与高盐（３００－５００ｍｍｏｌ／ＬＮａＣｌ）构象。在低盐溶液中，α－辅肌动蛋白含有较高比例的α－螺旋结构（３３－３４％），随着溶液中钠盐浓度的升高部分α－螺旋结构转变为β－转角或β－折叠结构。此外还研究了ｐＨ诱导α－辅肌动蛋白构象的变化，定量分析结果表明在ｐＨ７．０和中盐条件下（α－辅肌动蛋白交联Ｆ－ａｃｔｉｎ成束的活性最高），α－辅肌动蛋白β－转角结构含量最高，而α－螺旋结构含量较低。由此可见，β－转角结构在α－辅肌动蛋白交联肌动蛋白成束中可能具有重要的功能。
The changes of the secondary structure of α-actinin in different concentrations of NaCl solution were studied by FTIR. The results showed that α-actinin has at least three different conformations at different NaCl concentrations: low salt (30-90 mmol / L NaCl), medium salt (150 mmol / L-250 mmol / L NaCl) and high salt -500 mmol / LNaCl) conformation. Α-actinin contains a high proportion of α-helical structures (33-34%) in low-salt solutions. As the concentration of sodium in solution increases, part of the α-helical structure is converted to β-turn or β - Folding structure. In addition, the pH-induced changes in the conformation of α-actinin were also studied. The results of quantitative analysis showed that under the conditions of pH 7.0 and medium salt (α-actinin cross-linked F-actin has the highest activity) Actin actin β-turn structure highest content, and α-helical structure content is low. Thus, the β-turn structure may play an important role in bundling α-actinin-linked actin.