Estimation of binding constants by capillary electrophoresis

Capillary electrophoresis (CE) has become a useful technique for measuring binding constants. This review is focused on recent trends in the estimation of binding constants by affinity CE. First, we introduce several mathematical equations in which it is assumed that the stoichiometry of the binding between drug and protein is 1:1 as a simple model. In order to calculate accurate binding constants by affinity CE, several experimental considerations are described in this review. In addition, some recent methodologies, such as partial filling technique and multiple-step ligand injection method, are introduced. Among research publications within 3 years, recent applications for determining binding constants are reviewed.     

Multithermal titration calorimetry: a rapid method to determine binding heat capacities

Herein a new method that allows binding DeltaCp to be determined with a single experiment is presented. Multithermal titration calorimetry (MTC) is a simple extension of isothermal titration calorimetry (ITC) that explicitly takes into account the thermal dependences of DeltaH and the binding constant. Experimentally, this is accomplished by performing a single stepwise titration with ITC equipment, allowing temperature re-adjustments of the system at intermediate states of the titration process. Thus, from the resulting multitherm, DeltaCp can also be determined. The experimental feasibility of MTC was tested by using the well-characterized lysozyme-chitotriose complex as a model system.     

转铁蛋白糖链结构对受体亲和性的影响

用伴刀豆凝集素（ＣｏｎＡ）,小扁豆凝集素（ＬＣＡ）,和欧曼陀罗凝集素（ＤＳＡ）亲和层析法,分别从正常人血清转铁蛋白（Ｔｆ）和孕妇血清Ｔｆ中获得二天线糖链的Ｔｆ和多天线糖链的Ｔｆ．用于研究其对从胎盘中纯化得到的转铁蛋白受体（ＴｆＲ）的亲和性。经Ｓｃａｔｃｈａｒｄ作图结果发现,解离常数分别为：４．９７×１０－８ｍｏｌ／Ｌ和９．８０×１０－８ｍｏｌ／Ｌ．最大结合分别是１８０ｆｍｏｌ／Ｌ和１８２ｆｍｏｌ／Ｌ,表明含多天线糖链的Ｔｆ对受体的亲和性比二天线糖链的Ｔｆ降低１倍,而ＴｆＲ的结合位点数不变。     

Synthesis and biological evaluation of novel pyrimidine derivatives as sub-micromolar affinity ligands of GalR2

GalR1 and GalR2 represent unique pharmacological targets for treatment of seizures and epilepsy. A novel series of 2,4,6-triaminopyrimidine derivatives were synthesized and found to have sub-micromolar affinity for GalR2. Optimization of a series of 2,4,6-triaminopyrimidines led to the discovery of several analogs with IC50 values ranging from 0.3 to 1 μM.     

精氨加压素片段(4-8)对鼠脑PKC和PKA活性的影响

精氨加压素的 C端片段 ,AVP( 4 - 8) ,具有增强记忆的功能 ,它在大鼠脑内引发一系列的生理生化反应 .PKC经常是 G蛋白偶联受体信号传导途径中的介导激酶 ,在 AVP( 4 - 8)信号转导支路中亦不例外 .放射性配基结合实验表明 ,在海马及皮层突触膜上存在 AVP( 4 - 8)的特异性结合位点 .AVP( 4 - 8)可以刺激大鼠脑内 PKC酶活的升高 ,并可以被 AVP( 4 - 8)的受体拮抗剂 ZDC( C) PR阻断 .在同样条件下 ,AVP( 4 - 8)对 PKA酶活无显著性影响 .     

Quantitative structure-activity relationships and the prediction of MHC supermotifs

The underlying assumption in quantitative structure-activity relationship (QSAR) methodology is that related chemical structures exhibit related biological activities. We review here two QSAR methods in terms of their applicability for human MHC supermotif definition. Supermotifs are motifs that characterise binding to more than one allele. Supermotif definition is the initial in silico step of epitope-based vaccine design. The first QSAR method we review here--the additive method--is based on the assumption that the binding affinity of a peptide depends on contributions from both amino acids and the interactions between them. The second method is a 3D-QSAR method: comparative molecular similarity indices analysis (CoMSIA). Both methods were applied to 771 peptides binding to 9 HLA alleles. Five of the alleles (A*0201, A*0202, A*0203, A*0206 and A*6802) belong to the HLA-A2 superfamily and the other four (A*0301, A*1101, A*3101 and A*6801) to the HLA-A3 superfamily. For each superfamily, supermotifs defined by the two QSAR methods agree closely and are supported by many experimental data.