A label-free nanoparticle aggregation assay for protein complex/aggregate detection and study

作者：Bogdanovic Jelena; Colon Jimmie; Baker Cheryl; Huo Qun^*

来源：Analytical Biochemistry, 2010, 405(1): 96-102.

DOI：10.1016/j.ab.2010.06.008

• Gold nanoparticles
• Dynamic light scattering
• Protein aggregates
• GAPDH

The detection, analysis, and understanding of protein complexes/aggregates and their formation process are extremely important for biomolecular research, diagnosis, and biopharmaceutical development. Unfortunately, techniques that can be used conveniently for protein complex/aggregate detection and analysis are very limited. Using gold nanoparticle immunoprobes coupled with dynamic light scattering (DLS), we developed a label-free nanoparticle aggregation immunoassay (NanoDLSay) for protein aggregate detection and study. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a protein target used routinely in Western blot as a loading control, is demonstrated here as an example. Through this study, we discovered that GAPDH has a strong tendency to form large aggregates in certain buffer solutions at a concentration range of 10-25 mu g/ml. The strong light scattering property of gold nanoparticles immunoprobes greatly enhanced the sensitivity of the dynamic light scattering for protein complex/aggregate detection. In contrast to fluorescence techniques for protein complex and aggregation study, the protein targets do not need to be labeled with fluorescent probe molecules in NanoDLSay. NanoDLSay is a very convenient and sensitive tool for protein complex/aggregate detection and study.

• 出版日期2010-10-1