水溶液中氨基酸桥联环糊精二聚体的分子识别  

Molecular Recognition of Double Cyclodextrin Bridged with Amino Acid Derivatives in Aqueous Solution

作　　者：宋乐新[1] 

机构地区：[1]南京大学配位化学研究所配位化学国家重点实验室，南京210093

出　　处：《化学学报》2001年第8期1201-1209,共9页Acta Chimica Sinica

基　　金：国家自然科学基金

摘　　要：采用荧光偏光方法研究了用2-氨基-L-1,5-戊二酸衍生物和(1R,3R)-1-氨基-1,3-二羧基环戊烷衍生物桥联的环糊精二聚体1和2(主体),在298 K、pH=7.4时,与四个低分子量的多肽(客体,H-Trp-Trp-Arg-Arg-NH2 3;Adm-Trp-Arg-Arg-NH2 4;Adm-D-Trp-Arg-Arg-NH2 5;H-Trp-Trp-Trp-Trp-Arg-Arg-NH2 6)之间的相互作用.研究结果表明,二聚体环糊精对于多肽的分子识别作用,就主体而言,即便是主体作用位点以外部分基团结构的改变,对主-客体之间的分子识别也有重要影响,并且两个空腔在组装客体过程中相互之间产生协同作用.就客体而言,多肽分子的链长、疏水性及其嵌入基团的极性、大小、形状等对包合物的形成与稳定均起重要作用.主-客体组装过程中产生负的焓变和正的熵变,表明范德华-伦敦色散力、氢键和疏水相互作用是本文研究体系的主要包合驱动力.The interaction between four peptides with low molecular weight (guest, H - Trp - Trp - Arg Arg - NH2 3; Adm - Trp - Arg - Arg - NH2 4; Adm - D - Trp - Arg - Arg - NH2 5; H - Trp - Trp - Trp Trp - Arg - Arg - NH2 6) and cyclodextrin dimers (host, 1, 2) bridged with derivatives of glutamic acid or (1R, 3R) - 1 - aminocyclopentane - cis - 1, 3 - dicarboxylic acid was investigated by using fluorescence polarization method in aqueous buffer solution (pH 7.4) at 298 K. It was shown that the molecular recognition of a double cyclodextrin to a peptide is not only affected by the structure and properties of the bridging group between two cyclodextrins but also related to the chain length, hydrophobicity of a peptide and polarity, size and shape of the penetrating group. The changes in enthalpy (DeltaH(o)) and entropy (T DeltaS(o)) accompanying the complexation were determined in usual way. It was found that complexation is accompanied by negative changes in enthalpy and positive changes in entropy, indicating that van der Waals - Lodon dispersion, hydrogen bonding and hydrophobic interaction between a double cyclodextrin and a peptide are mainly responsible for the inclusion compound formation.

关 键 词：环糊精 氨基酸 包合物 分子识别 二聚体 桥联 分子组装 水溶液 

分 类 号：O641.3[理学—物理化学] O636.12[理学—化学]