Wild Type, Mutant Protein Unfolding and Phase Transition Detected by Single-Nanopore Recording

作者：Merstorf Celine; Cressiot Benjamin; Pastoriza Gallego Manuela; Oukhaled Abdelghani; Betton Jean Michel; Auvray Loic; Pelta Juan^*

来源：ACS Chemical Biology, 2012, 7(4): 652-658.

DOI：10.1021/cb2004737

Understanding protein folding remains a challenge. A difficulty is to investigate experimentally all the conformations in the energy landscape. Only single molecule methods, fluorescence and force spectroscopy, allow observing individual molecules along their folding pathway. Here we observe that single-nanopore recording can be used as a new single molecule method to explore the unfolding transition and to examine the conformational space of native or variant proteins. We show that we can distinguis unfolded states from partially folded ones with the aerolysin pore. The unfolding transition curves of the destabilized variant are shifted toward the lower values of the denaturant agent compared to the wild type protein. The dynamics of the partially unfolded wild protein follows a first order transition. The denaturation curve obtained with the aerolysin pore is similar to that obtained with the alpha hemolysin pore. The nanopore geometry or net charge does not influence the folding transition but changes the dynamics.

• 出版日期2012-4