A Cucurbit7uril-Ferrocene Complez Achieves Avidin-Biotin Affinity by Overcoming Enthalpy-Entropy Compensation
(0) 1.Introduction The design and characterization of synthetic host-guest pairs still represents an open challenge in supramolecular chemistry. Avidin-biotin complex is the strongest biological glue, achieving an extraordinarily high affinity of 1015 M-11,2 Cooperative, multiple, non-covalent interactions are essential for realizing such strong complexation and indeed the binding site of avidin is composed of an array of polar and aromatic residues, all of which cooperatively contribute to optimize biotin recognition and binding. Thus, several aromatic amino acid residues form a rigid hydrophobic box around the binding site and a number of polar residues stabilize the complex through a network of multiple hydrogen bonds. This complex structure induces a large negative enthalpy change (△H°) resulting from the formation of multiple hydrogen bonds, as well as robust van der Waals contacts inside the hydrophobic box.3 At the same time, a large negative entropy change (△S°) is expected due to the severe restriction of the biotin motion upon comptcxation with avidin. This effect is, however, cancelled by a large, positive entropy of dcsolvation, eventually making the overall entropy of complexation nearly zero.3
supramolecular chemistry entropy control avidin-biotin complez
Yoshihisa Inoue Mikhail Rekharsky Tadashi Mori Cheng Yang Young Ho Ko N.Selvapalam Hyunuk Kim Kimoon Kim
Department of Applied Chemistry,Osaka University,Suita,Japan Center for Smart Supramolecules,Pohang University of Science and Technology,Pohang,Korea
国际会议
江苏镇江
英文
111-113
2008-10-15（万方平台首次上网日期，不代表论文的发表时间）