Hendrickson Olga D, Zherdev Anatoly V, Kaplun Alexander P, Dzantiev Boris B
Institute of Biochemistry Russian Academy of Science, Leninsky Prospect 33, 119071 Moscow, Russia.
Mol Immunol. 2002 Nov;39(7-8):413-22. doi: 10.1016/s0161-5890(02)00175-x.
Unilamellar liposomes with incorporated hapten-phospholipid conjugates were proposed as models of polyvalent antigens with migrating determinants for quantitative analysis of their interaction with antibodies. The monovalent pesticide atrazine was used as a model antigen. For its incorporation into the lipid bilayer, the atrazine carboxylated derivative was conjugated with dimyristoylphosphatidylethanolamine (DMPE). Unilamellar liposomes were prepared with dimyristoylphosphatidylcholine/atrazine-DMPE at molar ratios of 90:10, 95:5, 98:2, 99:1 and 99.5:0.5. Their interaction with the peroxidase-labeled anti-atrazine antibodies was studied by enzyme immunoassay and polarization fluoroimmunoassay techniques. It was shown that the increase in hapten content in the liposomes from 0.5 to 10 mol% led to an increase in the equilibrium constants of the interaction with antibodies from 0.093 x 10(8) to 0.303 x 10(8)M-1. The association rate constants varied from 1.45 x 10(5) to 15.5 x 10(5)M-1 s-1 depending on the antigen content in liposomes and experimental conditions. The measured constants were applied for a mathematical model describing multi-step interaction between antibodies and polyvalent liposomal antigens. The model adequately describes the quantitative regularities of the influence of antigen content and the affinity of immunochemical interaction on the quantity and the dynamics of the immune complexes forming.
含有半抗原 - 磷脂共轭物的单层脂质体被提议作为具有迁移决定簇的多价抗原模型，用于定量分析其与抗体的相互作用。单价农药阿特拉津用作模型抗原。为了将其掺入脂质双层，阿特拉津羧化衍生物与二肉豆蔻酰磷脂酰乙醇胺（DMPE）共轭。用二肉豆蔻酰磷脂酰胆碱/阿特拉津 - DMPE以90:10、95:5、98:2、99:1和99.5:0.5的摩尔比制备单层脂质体。通过酶免疫测定和偏振荧光免疫测定技术研究了它们与过氧化物酶标记的抗阿特拉津抗体的相互作用。结果表明，脂质体中半抗原含量从0.5 mol％增加到10 mol％，导致与抗体相互作用的平衡常数从0.093×10⁸增加到0.303×10⁸ M⁻¹。结合速率常数根据脂质体中的抗原含量和实验条件在1.45×10⁵至15.5×10⁵ M⁻¹ s⁻¹之间变化。所测得的常数被应用于描述抗体与多价脂质体抗原之间多步相互作用的数学模型。该模型充分描述了抗原含量和免疫化学相互作用亲和力对免疫复合物形成数量和动力学影响的定量规律。
