A novel method to predict protein aggregations using two-dimensional native protein microfluidic chip electrophoresis

As is known, protein aggregation is involved in several diseases such as amyloid aggregation. Control of protein aggregation is also a challenge to protein pharmaceuticals. Thus, efficient analytical tools used to predict protein aggregation in the early potential or intermediate stage in a complex sample are crucial to the understanding and prevention of protein aggregation. However, it is always difficult to study early state and microscopy invisible aggregation. In this study, a simple analytical technology based on isoelectric focusing (IEF) and capillary zone electrophoresis (CZE) coupled two-dimensional microfluidic chip native protein electrophoresis was established to study aggregation before the formation of the visible aggregated particles. With IEF aggregation promotion and CZE separation, α-synuclein aggregation was easily observed through whole channel detection, not only in the whole protein extraction of α-synuclein stably overexpressing PC12 cells, but also of AD rat hippocampi. This method was also used to investigate the effects of two drugs on the inhibition or promotion of protein aggregation in PC12 cells, respectively. Further combined with histogram image analysis, this easy, efficient, robust and quantitative protein aggregation prediction of crude sample demonstrates the speciality and great potential of this new method in disease research, drug development and the biopharmaceutical industry. At the same time, our research also expands the application field of chip electrophoresis because, for the first time, chip electrophoresis was used as a separation based aggregation display tool.