Formation of Superstructural Bilayers and Enzyme Model Reaction by Telomer-type Surfactants.

1. 合成了具有聚l -谷氨酸和聚l -天冬氨酸头基的双链烷基衍生物，并研究了它们在稀水溶液中的聚集体形态。这些多氨基酸衍生物分散在pH 4以上的水中，形成由单壁双层膜组成的多种螺旋超结构，其形态与亲水性头基的化学结构密切相关。不含聚氨基酸头基的铵类两亲体、低分子头基或聚dl -氨基酸头基的两亲体均未观察到相应的螺旋结构。通过观察聚l -天冬氨酸衍生物在水溶液中的双聚体再聚集体的变形，得出了螺旋超结构的形成机制：通过培养产生的未扭曲的细丝形成双螺旋或多重螺旋，从而诱导螺旋结构的形成。研究了在两亲分子聚赖氨酸头基形成的手性基质胶束存在的情况下，非手性羟肟酸对手性酯的裂解作用。结果总结如下：(1)仅手性胶束碱性水解未观察到对映体选择性。这个矩阵没有选择性。当非手性羟肟酸加入体系时，诱导了选择性。(2)基质胶束的肽段形成的二级结构的构象变化使选择性方向发生逆转。在随机线圈条件下观察到l选择性，在< α > -螺旋条件下观察到d选择性。(3)选择性程度取决于羟肟酸的化学结构；例如，N-H型羟肟酸比n -甲基型羟肟酸具有更高的选择性。因此，推测手性胶束与非手性亲核试剂之间的手性相互作用引入了对映选择性，其中多肽片段的构象起着重要作用。少

1. Double-chain alkyl derivatives with poly(L-glutamic acid)- and poly(L-aspartic acid)-head groups were synthesized and their aggregate morphologies in dilute aqueous solutions were investigated. These polyamino acid derivatives were dispersed in water at above pH 4 to form a variety of helical superstructures composed of single-walled bilayer membranes, whose morphologies were closely related to the chemical structures of hydrophilic head groups. The helical structures were not observed in the corresponding ammonium amphiphiles without polyamino acid-head groups and the amphiphile with low-molecular head groups or with poly(DL-amino acid) head groups. The developmental mechanism to helical superstructures was concluded by following the metamorphosis of bilay reaggregates from poly(L-aspartic acid) derivatives in aqueous solutions:the helical forms are induced via the formation of double or multiple helix among the untwisted filaments produced by incubating.2. Chiral ester cleavage by … More achiral hydroxamic acids was investigated in the presence of chiral matrix micelles formed from amphiphiles with poly-L-lysine-head groups. The results are summarized as follows. (1) The enantioselectivity was not observed in the alkaline hydrolysis in chiral micelles only. This matrix possesses no selectivity. When an achiral hydroxamic acid was added to the system,selectivity was induced. (2) The direction of selectivity is reversed by the conformational change of the secondary structure formed by the peptide moiety of matrix micelles. L-Selectivity in the random coil and D-selectivity in the <alpha> -helix condition were observed. (3) The degree of selectivity is dependent on the chemical structure of hydroxamic acid;for example, an N-H type hydroxamic acid gives higher selectivity than an N-methyl type one. Thus, it is supposed that enantioselectivity is introduced by the chiral interaction between chiral micelles and achiral nucleophiles, in which the conformation of polypeptide moiety plays an important role. Less