超声衰减检测法研究大分子构象变化

Applications of Ultrasonic Attenuation Measurements in the Studies of Macromolecular Conformational Behaviors

以壳聚糖(CS)包埋聚N-异丙基丙烯酰胺(PNIPAM)水凝胶和聚甲基丙烯酸(PMAA)水溶液为模型体系,研究了超声衰减检测法用于探测大分子溶液构象和聚集态变化的可能性.实验表明,超声衰减参量(α)与大分子在溶液或水凝胶中的构象状态密切相关.一般而言,大分子的松散线团构象具有较低的超声衰减能力,而压缩线团构象则具有比较高的超声衰减能力.不过,过度压缩线团构象的超声衰减能力也比较小.据此,可以预期超声衰减检测有可能发展成为一种简单、非破坏性大分子构象研究新方法.

The applicability of ultrasonic attenuation measurements in the studies of the conformational behaviors of macromolecules in aqueous phase and hydrogels was studied with glutaraldehyde(Glu) cross linked chitosan(CS) hydrogel containing poly(N - isopropylacrylamide) (PNIPAM) and the aqueous solution of poly(methacrylic acid) (PMAA) as model systems. It was shown that the conformations adopted by the macromolecules are well related to the values of the attenuation parameter(cr). The open coil conformation corresponds to a smaller ct value, and a compact coil conformation corresponds to a larger a value. It does not follow, however, that the more compact the coil conformation, the greater the a value, In fact, a too compact coil conformation corresponds to a quite small a value. Based upon these studies, it is predicted that the ultrasonic attenuation measurements may be developed into a simple, effective and non - destructive technique for the studies of macromolecular behaviors in aqueous and hydrogel phases.