Peula J M, Hidalgo-Alvarez R, de las Nieves F J
Department of Applied Physics, University of Granada, Spain.
J Biomater Sci Polym Ed. 1995;7(3):241-51. doi: 10.1163/156856295x00283.
The present work deals with the study of the colloidal stability and immunoreactivity of sulfonated polystyrene latex particles covered by different amounts of m-BSA and IgG/a-CRP. These proteins have been previously adsorbed onto a sulfonated latex by sequential and competitive coadsorption experiments and it was possible to obtain latex-protein particles with different degrees of coverage by each protein. The latex particles, fully or partially covered by each protein (termed latex-protein complexes), were resuspended under several conditions (different pH and ionic strength values) and their colloidal stability, vs the addition of the electrolyte was studied using turbidity measurements. This stability appeared at a high degree of coverage by BSA and at a pH in which the BSA was negatively charged. At a high degree of coverage by IgG, the latex particles were unstable at all pHs. As a final part of this work, the immunoreactivity of several complexes was studied following the changes in the turbidity after the addition of CRP antigen. Only the complexes which were colloidally stable gave detectable reactivity. However, the complexes with a relatively low degree of coverage by IgG/a-CRP gave good immunoreactivity. Therefore, the latex-protein complex properties depended on the percentage of BSA or IgG adsorbed and on the electric state of the proteins at the redispersion pH. Under specific incubation conditions, sulfonated latex covered by significant IgG/BSA percentages was obtained, which showed a high colloidal stability and good immunoreactivity.
本工作研究了被不同量的间位牛血清白蛋白（m-BSA）和免疫球蛋白G/抗C反应蛋白（IgG/a-CRP）覆盖的磺化聚苯乙烯胶乳颗粒的胶体稳定性和免疫反应性。这些蛋白质先前已通过顺序和竞争性共吸附实验吸附到磺化胶乳上，并且有可能获得每种蛋白质具有不同覆盖度的胶乳-蛋白质颗粒。将完全或部分被每种蛋白质覆盖的胶乳颗粒（称为胶乳-蛋白质复合物）在几种条件下（不同的pH值和离子强度值）重新悬浮，并使用浊度测量研究它们相对于添加电解质的胶体稳定性。这种稳定性在牛血清白蛋白高度覆盖且牛血清白蛋白带负电荷的pH值下出现。在免疫球蛋白G高度覆盖时，胶乳颗粒在所有pH值下都不稳定。作为这项工作的最后一部分，在添加C反应蛋白抗原后，通过浊度变化研究了几种复合物的免疫反应性。只有胶体稳定的复合物才有可检测到的反应性。然而，被免疫球蛋白G/抗C反应蛋白覆盖度相对较低的复合物具有良好的免疫反应性。因此，胶乳-蛋白质复合物的性质取决于吸附的牛血清白蛋白或免疫球蛋白G的百分比以及在再分散pH值下蛋白质的电状态。在特定的孵育条件下，获得了被显著百分比的免疫球蛋白G/牛血清白蛋白覆盖的磺化胶乳，其表现出高胶体稳定性和良好的免疫反应性。
