Stokrová S, Bohdanecký M, Bláha K, Sponar J
Biopolymers. 1989 Oct;28(10):1731-44. doi: 10.1002/bip.360281007.
Conformational transitions of basic sequential polytripeptides (Lys-Ala-Leu)n, (Arg-Ala-Ala)n, (Arg-Leu-Ala)n, and (Arg-Ala-Leu)n, induced by elevated salt concentrations and/or temperatures in aqueous solutions, were investigated by CD, sedimentation equilibrium, and viscometry. The behavior of (Lys-Ala-Leu)n was compared with that of the sequential isomer (Lys-Leu-Ala)n, studied previously. It was found that both polypeptides are highly helical with a tendency to aggregate in high salt solutions. Although the hydrophobic interactions between Lys and Leu residues play an important role in both cases, the final effect on helix stabilization and aggregation is different. The Arg-containing polypeptides were found to assume the alpha-helical conformation. Compared to the Lys-containing polypeptides (Lys-Ala-Leu)n and (Lys-Leu-Ala)n, a very low tendency to aggregate was observed.
通过圆二色光谱（CD）、沉降平衡和粘度测定法，研究了在水溶液中，由盐浓度升高和/或温度升高诱导的碱性序列型聚三肽（Lys-Ala-Leu）n、（Arg-Ala-Ala）n、（Arg-Leu-Ala）n和（Arg-Ala-Leu）n的构象转变。将（Lys-Ala-Leu）n的行为与先前研究的序列异构体（Lys-Leu-Ala）n进行了比较。发现这两种多肽都具有高度螺旋性，并且在高盐溶液中有聚集倾向。尽管Lys和Leu残基之间的疏水相互作用在这两种情况下都起着重要作用，但对螺旋稳定性和聚集的最终影响是不同的。发现含Arg的多肽呈现α-螺旋构象。与含Lys的多肽（Lys-Ala-Leu）n和（Lys-Leu-Ala）n相比，观察到其聚集倾向非常低。
