Archer B G, Krakauer H
Biochemistry. 1977 Feb 22;16(4):615-7. doi: 10.1021/bi00623a010.
The thermodynamic parameters which characterize the binding of dinitrophenylglycine and dinitrophenylmethoxypoly(ethylene glycol) to selected affinity classes of equine IgG and IgG(T) antibodies were determined by fluorescence quenching and flow calorimetry. The binding enthalpies and entropies were in all cases large and negative, falling in the ranges -14 to -17 kcal/mol and -18 to -25 eu, respectively. The differences in the enthalpies and entropies of binding for different affinity classes and for different haptens are discussed with reference to differences in the structures of the haptens studied and as indications of differences in binding site structure. In addition, the apparent existence of fluorescent side chains which can transfer energy to either hapten binding site in IgG(T) antibodies but not in IgG antibodies is interpreted as indicative of a smaller average interbinding site distance in IgG(T) than in IgG antibodies.
通过荧光猝灭和流动量热法测定了表征二硝基苯基甘氨酸和二硝基苯基甲氧基聚乙二醇与马IgG和IgG(T)抗体的选定亲和类结合的热力学参数。在所有情况下，结合焓和熵都很大且为负，分别落在-14至-17千卡/摩尔和-18至-25熵单位的范围内。结合不同亲和类和不同半抗原的结合焓和熵的差异，将结合所研究的半抗原结构差异进行讨论，并作为结合位点结构差异的指示。此外，在IgG(T)抗体中可将能量转移至任一半抗原结合位点但在IgG抗体中却不能的荧光侧链的明显存在，被解释为表明IgG(T)中平均结合位点间距离比IgG抗体中的更小。
