QUENCHING OF FLUORESCEIN-CONJUGATED LIPIDS BY ANTIBODIES - QUANTITATIVE RECOGNITION AND BINDING OF LIPID-BOUND HAPTENS IN BIOMEMBRANE MODELS, FORMATION OF 2-DIMENSIONAL PROTEIN DOMAINS AND MOLECULAR-DYNAMICS SIMULATIONS
QUENCHING OF FLUORESCEIN-CONJUGATED LIPIDS BY ANTIBODIES - QUANTITATIVE RECOGNITION AND BINDING OF LIPID-BOUND HAPTENS IN BIOMEMBRANE MODELS, FORMATION OF 2-DIMENSIONAL PROTEIN DOMAINS AND MOLECULAR-DYNAMICS SIMULATIONS
复制标题
DOI：
10.1016/s0006-3495(92)81645-4
复制
发表时间：
1992-09-01
影响因子：
3.4
通讯作者：
SALESSE, C
中科院分区：
文献类型：
--
作者：
AHLERS, M;GRAINGER, DW;SALESSE, C
三个模型生物膜系统，单层，胶束和囊泡，已被用来研究半抗原介绍在膜界面上的抗体结合的化学和物理变量的影响。监测针对半抗原产生的抗荧光素单克隆抗体4-4-20的半抗原识别和结合。荧光素，在这些膜模型中作为荧光素缀合的脂质结构的函数。在该系统中的特异性识别和结合通过在荧光素渗透到抗体的活性位点时荧光素发射的猝灭来方便地监测。脂质结构被证明在影响抗体淬灭中起很大作用。有趣的是，所观察到的淬灭程度几乎与所研究的脂质膜模型无关，但与脂质的化学结构直接相关。在所有情况下，抗体最有效地识别和淬灭基于双十八胺的脂质，其中荧光素通过长的柔性亲水性间隔基连接到头基。含有荧光素头基的二棕榈酰磷脂酰乙醇胺仅表现出部分结合/淬灭。具有荧光素头基的卵磷脂酰乙醇胺对抗体识别、结合或淬灭没有敏感性。还提出了抗体与单层荧光素脂质结合后二维蛋白质结构域的形成。在膜表面对这些抗体-半抗原复合物的化学和物理要求已经在基于该抗体-半抗原复合物的最近晶体学模型的分子动力学模拟方面进行了讨论（Herron等人，1989.蛋白质结构功能Genet. 5：271-280）。
Three model biomembrane systems, monolayers, micelles, and vesicles, have been used to study the influence of chemical and physical variables of hapten presentation at membrane interfaces on antibody binding. Hapten recognition and binding were monitored for the anti-fluorescein monoclonal antibody 4-4-20 generated against the hapten. fluorescein, in these membrane models as a function of fluorescein-conjugated lipid architecture. Specific recognition and binding in this system are conveniently monitored by quenching of fluorescein emission upon penetration of fluorescein into the antibody's active site. Lipid structure was shown to play a large role in affecting antibody quenching. Interestingly, the observed degrees of quenching were nearly independent of the lipid membrane model studied, but directly correlated with the chemical structure of the lipids, In all cases, the antibody recognized and quenched most efficiently a lipid based on dioctadecylamine where fluorescein is attached to the headgroup via a long, flexible hydrophilic spacer. Dipalmitoyl phosphatidylethanolamine containing a fluorescein headgroup demonstrated only partial binding/quenching. Egg phosphatidylethanolamine with a fluorescein headgroup showed no susceptibility to antibody recognition, binding, or quenching. Formation of two-dimensional protein domains upon antibody binding to the fluorescein-lipids in monolayers is also presented. Chemical and physical requirements for these antibody-hapten complexes at membrane surfaces have been discussed in terms of molecular dynamics simulations based on recent crystallographic models for this antibody-hapten complex (Herron et al., 1989. Proteins Struct. Funct. Genet. 5:271-280).