Nature头条：蛋白质折叠到底有多快？答案揭晓

Core Viewpoint - The recent study published in Physical Review Letters reveals the transition-path time for protein folding, which is measured to be between 0.7 to 4 microseconds, indicating that the core process of proteins transitioning from an unfolded to a folded state occurs almost instantaneously [5][11]. Group 1: Protein Folding Mechanism - The study highlights that the time required for protein folding is independent of the protein's sequence or size, suggesting that more complex proteins can fold more efficiently than simpler biological macromolecules like DNA [5][11]. - The research utilized advanced nanophotonics-enhanced single-molecule fluorescence spectroscopy to capture the rapid transition period of protein folding, which was previously difficult to measure due to limitations in time resolution [6][7]. Group 2: Findings on Protein Characteristics - The findings indicate that longer protein sequences exhibit a greater diffusion coefficient during folding, which facilitates a smoother transition over energy barriers, contrary to expectations that larger proteins would fold more slowly [10]. - The study introduces the concept of "energy landscape," explaining that proteins with more internal interactions among amino acids tend to fold more efficiently, as these interactions create a smoother energy landscape [10][11]. Group 3: Comparative Analysis with Other Biomolecules - The folding time of natural proteins is significantly faster than that of other biomolecules, such as DNA, which takes approximately 20-30 microseconds to fold into a hairpin structure, and designed proteins that may take tens of microseconds to milliseconds [11]. - The research suggests that natural selection has optimized the energy landscape of proteins, minimizing roughness and avoiding non-natural interactions, leading to more efficient folding processes [11].