Single-molecule biotechnology for protein researches

Abstract Cells employ proteins to perform metabolic functions and maintain active physiological state through charge transfer and energy conversion. These processes are carried out in a narrow space precisely and rapidly, which, no doubt, bring great difficulty for their detection and dissection. Fortunately, in recent years, the development and expansion of single-molecule technique in protein research make monitoring the dynamical changes of protein at single-molecule level a reality, which also provides a powerful tool for the further exploration of new phenomena and new mechanisms of life activities. This paper aims to summarize the working principle and essential achievements of single-molecule technique in protein research in recent five years. We focus on not only dissecting the difference of nanopores, atomic force microscope, scanning tunneling microscope, and optical tweezers technique, but also discussing the great significance of these single-molecule techniques in investigating intramolecular and intermolecular interactions, electron transport, and conformational changes. Finally, the opportunities and challenges of the single-molecule technique in protein research are discussed, which provide a new door for single-molecule protein research.