Walsh J, Gosling J P
Anal Biochem. 1986 Nov 1;158(2):413-23. doi: 10.1016/0003-2697(86)90569-5.
The adsorption of radioiodinated rabbit IgG and bovine serum albumin (BSA) to polystyrene tubes was investigated. Adsorption isotherms where the proportion of the protein bound was relatively constant over a range of intermediate protein concentrations, and where the proportion bound was protein dependent, were obtained. To investigate the effects of radioiodination, proteins labeled to give a wide range of substitution ratios (0.03 to 3.7 125I/protein molecule) were employed. While labeling did not appear to affect BSA adsorption, the kinetics of IgG binding were altered in a number of ways. The proportion bound in the concentration independent region was decreased even at substitution ratios less than or equal to 0.2. In addition, while all preparations of iodinated BSA, and IgG preparations with less than or equal to 1.6 125I/IgG, gave bimodal adsorption isotherms, with more heavily labeled IgG (greater than or equal to 2.5 125I/IgG) the apparent high affinity binding to the plastic surface was abolished. These results indicate that radioiodination substantially alters the kinetics of the binding of IgG to polystyrene. In addition, the results obtained are discussed with respect to previous relevant and often apparently contradictory findings.
研究了放射性碘化兔免疫球蛋白G（IgG）和牛血清白蛋白（BSA）在聚苯乙烯管上的吸附情况。得到了吸附等温线，在一系列中等蛋白浓度范围内，结合蛋白的比例相对恒定，且结合比例取决于蛋白。为了研究放射性碘化的影响，使用了标记后具有广泛取代率（0.03至3.7个125I/蛋白分子）的蛋白质。虽然标记似乎不影响BSA的吸附，但IgG结合的动力学在多个方面发生了改变。即使在取代率小于或等于0.2时，浓度独立区域内的结合比例也会降低。此外，虽然所有碘化BSA制剂以及取代率小于或等于1.6个125I/IgG的IgG制剂都给出了双峰吸附等温线，但对于标记程度更高的IgG（大于或等于2.5个125I/IgG），其与塑料表面的明显高亲和力结合被消除。这些结果表明，放射性碘化显著改变了IgG与聚苯乙烯结合的动力学。此外，还结合先前相关且往往明显相互矛盾的研究结果对所得结果进行了讨论。
