Holmberg Maria, Stibius Karin B, Ndoni Sokol, Larsen Niels B, Kingshott Peter, Hou Xiaolin L
Danish Polymer Centre, Risø National Laboratory, DK-4000 Roskilde, Denmark.
Anal Biochem. 2007 Feb 1;361(1):120-5. doi: 10.1016/j.ab.2006.11.016. Epub 2006 Dec 4.
Protein adsorption on modified and unmodified polymer surfaces investigated through radiolabeling experiments showed a tendency for higher than expected albumin and immunoglobulin G (IgG) adsorption. Possible enhanced protein aggregation and degradation caused by the iodine labeling method used were analyzed through chromatography and spectroscopy techniques. Results show that the iodine labeling method using chloramine-T (CAT) as an oxidizing agent can cause both enhanced aggregation and fragmentation of proteins. Albumin shows an enhanced tendency to aggregate after iodine labeling using the CAT method, and higher amounts of fragmentation are observed for CAT-labeled IgG molecules relative to unlabeled IgG molecules as well as to IgG molecules labeled using the Iodo-Gen method. These results show that the widely applied method of radioisotope labeling for quantitative assessment of protein adsorption should be used with caution and preferably should be validated by a label-free methodology for each combination of radiolabel and protein. The results obtained in this study can be used to optimize investigation of protein adsorption on surfaces of materials for biomedical devices.
通过放射性标记实验对修饰和未修饰聚合物表面上蛋白质吸附的研究表明，白蛋白和免疫球蛋白G（IgG）的吸附量有高于预期的趋势。通过色谱和光谱技术分析了所用碘标记方法可能导致的蛋白质聚集增强和降解。结果表明，以氯胺-T（CAT）作为氧化剂的碘标记方法可导致蛋白质聚集增强和片段化。采用CAT法进行碘标记后，白蛋白显示出增强的聚集趋势，相对于未标记的IgG分子以及采用碘珠法标记的IgG分子，观察到CAT标记的IgG分子有更高程度的片段化。这些结果表明，广泛应用的用于蛋白质吸附定量评估的放射性同位素标记方法应谨慎使用，并且最好针对每种放射性标记与蛋白质的组合通过无标记方法进行验证。本研究获得的结果可用于优化生物医学设备材料表面蛋白质吸附的研究。
