Absorption spectroscopy of the complexation between superpotent guanidinium sweeteners and specific monoclonal antibodies.
Absorption spectroscopy of the complexation between superpotent guanidinium sweeteners and specific monoclonal antibodies.
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超强胍盐甜味剂和特定单克隆抗体之间络合的吸收光谱。
DOI：
10.1016/1357-2725(95)00001-6
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Linthicum,DS
中科院分区：
文献类型：
--
作者：
Droupadi,PR;Linthicum,DS
光谱研究抗体-抗原相互作用可以提供有用的信息，相互作用的模体和分子间缔合过程中涉及的能量。在这项研究中，我们使用吸收光谱法来研究五种不同的单克隆抗体（mAb）和四种超强配体甜味剂之间的相互作用。利用230-800 nm波长范围内吸收光谱的定量变化测定mAb-配体复合物的固有缔合常数和热力学参数。发现mAb-配体复合物的固有缔合常数在107- 105 IM − 1的范围内，并且与先前的放射免疫测定结果一致。对于两种单克隆抗体，在340 nm范围内的光谱中的定性变化，可以确定和相关的胍配体和芳香族残基的mAb的结合位点之间的电荷转移相互作用的存在。在具有两种不同甜味剂配体的mAb NC10.8中观察到电荷转移光谱。通过van 't霍夫图分析配体-mAb相互作用的热力学参数，并且在几乎所有情况下，发现反应是由热力学驱动的。固有的亲和力和热力学参数的测定可能是有用的抗体结合口袋和预测的配体对接方向的计算机辅助分子建模研究。发现抗体NC6.8与这组甜味剂配体以与它们的甜味效力相关的等级顺序反应，并且NC6.8的光谱发现与Fab-配体晶体结构的X射线衍射数据一致。这些研究可能揭示这些超强甜味剂配体的分子性质及其与推定的味觉受体的相互作用。
Spectroscopic studies of antibody-antigen interactions can provide useful information about the interactive motifs and energetics involved in the intermolecular association process. In this study we used absorption spectroscopy to examine the interactions between five different monoclonal antibodies (mAb) and four superpotent ligand sweeteners. Quantitative changes in the absorption spectra in the wavelength range of 230–800 nm were utilized for the determination of intrinsic association constants and thermodynamic parameters of the mAb-ligand complexes. The intrinsic association constants for the mAb-ligand complexes were found to be in the range of 107–105IM−1and were in agreement with previous radioimmunoassay determinations. For two mAb, qualitative changes in the spectra in the 340 nm range could be identified and were related to the presence of charge-transfer interaction between the guanidinium ligand and aromatic residues in the binding site of the mAb. A charge transfer spectra was observed in mAb NC10.8 with two different sweetener ligands. The thermodynamic parameters of the ligand-mAb interactions were analyzed by van't Hoff plots and in almost all cases the reactions were found to be enthalpically driven. The determinations of intrinsic affinity and thermodynamic parameters may be useful in computer-aided molecular modelling studies of the antibody binding pocket and predicted ligand docking orientations. Antibody NC6.8 was found to react with this set of sweetener ligands in a rank order that is related to their sweetness potencies and the spectroscopic findings for NC6.8 are in agreement with the X-ray diffraction data of the Fab-ligand crystal structures. These studies may shed light on the molecular nature of these superpotent sweetener ligands and their interactions with putative taste receptors.