Solid-state nanopore analysis on conformation change of p53TAD–MDM2 fusion protein induced by protein–protein interaction

Abstract

Although protein–protein interactions (PPIs) are emerging therapeutic targets for human diseases, development of high-throughput screening (HTS) technologies against PPI targets remains challenging. In this study, we propose a protein complex structure to effectively detect conformational changes of protein resulting from PPI using solid-state nanopore for a novel, widely-applicable drug screening method against various PPI targets. To effectively detect conformational changes resulting from PPI, we designed a fusion protein MLP (MDM2-linker-p53TAD), where p53TAD and MDM2 are connected by a 16 amino acid linker. The globular conformation of MLP exhibited a single-peak translocation event, whereas the dumbbell-like conformation of nutlin-3-bound MLP revealed as a double-peak signal. The proportion of double-peak to single-peak signals increased from 9.3% to 23.0% as nutlin-3 concentration increased. The translocation kinetics of the two different MLP conformations with varied applied voltage were analyzed. Further, the fractional current of the intra-peak of the double-peak signal was analyzed, probing the structure of our designed protein complex. This approach of nanopore sensing may be extendedly employed in screening of PPI inhibitors and protein conformation studies.