Construction and functionality as membrane of bundle polypeptides

以b-苄基- l-谷氨酸n -羧基酸酐（BLG-NCA）和六基（4-苄基-1-氧）环三磷hazene （AMOP）为原料，制备了以环三磷hazene为核心的六臂聚（β -苄基- l-谷氨酸）（S-PBLG），并对其构象和作为对端选择性膜的功能进行了研究。GPC法和光散射法测定的S-PBLG分子量与投料比、[BLG-NCA]/[AMOP]和转化率计算值基本一致，且分布较窄（M_w/M_n=1.1 ~ 1.3）。当在CDCl_3 （[BLG-NCA]/[AMOP]=10）中加入AMOP时，^1H NMR谱显示，在3.8 ppm处可归属于苄基质子的峰立即消失，BLG-NCA的转化率为0.57%。这些结果表明，AMOP中所有的氨基都能立即引发BLG-NCA的聚合，并且聚合物链的长度从磷烯c发散出来，并且得到了很好的控制。正如预期的那样，S-PBLG薄膜的IR和CD光谱分别在1653和1550cm^<-1>处出现峰值，在226nm处出现负峰，表明六臂聚谷氨酸盐呈右手a-螺旋结构。已知苯氧环三磷腈中的有机基团与几乎是平面的环三磷腈近似垂直排列。如果这种几何排列对S-PBLG成立，那么可以合理地假设刚性的谷氨酸链来自于磷腈环两侧的3 α -螺旋束结构。在S-PBLG末端氨基上引入芘的准分子的形成行为支持了这一点。采用三甘醇单甲醚（TEG）取代苯基制备膜。这种聚谷氨酸再次采用螺旋结构，如CD和IR光谱所证明的那样。研究了色氨酸（Trp）通过膜的对映选择性渗透。该膜仅渗透d -色氨酸，并且在超过200小时的时间内实现了完全的光学分辨率。对照实验表明，以三甘醇单甲醚为单元的常规聚谷氨酸没有溶解再酸盐的能力。这些结果表明，从线性到短氧乙烯链的六臂聚谷氨酸的结构变化带来了优异的光学异构体的分子识别能力，即具有短侧链的螺旋结构的组装对于获得高对映选择性是重要的。少

Hexaarmed poly (beta-benzyl-L-glutamates) (S-PBLG) with cyclotriphosphazene core were prepared by the polymerization of N-carboxy anhydride of b-benzyl-L-glutamate (BLG-NCA) with hexakis (4-benzylamino-1-oxy) cyclotriphosphazene (AMOP), and the conformation and the functionality as an enatioselctive membrane of resulting polymers were investigated. The molecular weights of S-PBLG determined by the combination of GPC and light scattering method were consistent with calculated values from the feed ratio, [BLG-NCA]/[AMOP], and conversion, and their distributions were narrow (M_w/M_n=1.1-1.3). When AMOP was added to BLG-NCA in CDCl_3 ([BLG-NCA]/[AMOP]=10), ^1H NMR spectra showed that the peak at 3.8 ppm assignable to benzyl proton disappeared immediately, together with the conversion of BLG-NCA of ca.57%. From these results, it appears that all of amino group in AMOP initiate the polymerization of BLG-NCA without delay and that the lengths of polymer chains diverging from the phosphazene c … More ore are well controlled. As expected, IR and CD spectra of S-PBLG film showed peaks at 1653 and 1550cm^<-1> and a negative peak at 226nm, respectively, indicating that the hexaarmed polyglutamates take a right handed a-helical structure. The organic group in phenoxycyclotriphosphazenes is known to be aligned approximately perpendicular to the almost planar cyclotriphosphazene. If this geometrical arrangement holds for S-PBLG,it seems reasonable to assume that the rigid polyglutamate chains from 3 alpha-helix bundle structure on both sides of phosphazene ring. This was supported by the behavior of the formation of excimer of pyrene which was introduced at terminal amino groups of S-PBLG.The membrane was prepared by displacement of benzyl group with triethylene glycol monomethyl ether (TEG). This polyglutamate again takes an alpha-helical structure, as evidenced by CD and IR spectra. The enantioselective permeation of tryptophan (Trp) through the membrane was examined. The membrane permeates only D-Trp and a complete optical resolution is achieved for over 200h. Control experiments showed that the conventional polyglutamate with triethylene glycol monomethyl ether units has no ability to resolve the recemate. These results indicate that the structural change from linear to hexaarmed polyglutamates with short oxyethylene chains brings about excellent abilities of molecular recognition of the optical isomer, i, e., the assembly of the helical structure with short side chains is important to attain a high enantioselectivity of the membrane. Less