title: Wild type, mutant protein unfolding and phase transition detected by single-nanopore recording.
abstract: 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 distinguish 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 type protein follows a first-order transition. The denaturation curve obtained with the aerolysin pore is similar to that obtained with the α-hemolysin pore. The nanopore geometry or net charge does not influence the folding transition but changes the dynamics.
authors.forename: Céline
authors.initials: C
authors.lastname: Merstorf
authors.forename: Benjamin
authors.initials: B
authors.lastname: Cressiot
authors.forename: Manuela
authors.initials: M
authors.lastname: Pastoriza-Gallego
authors.forename: Abdelghani
authors.initials: A
authors.lastname: Oukhaled
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Betton
authors.forename: Loïc
authors.initials: L
authors.lastname: Auvray
authors.forename: Juan
authors.initials: J
authors.lastname: Pelta
mesh_terms: D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics; D050505:Mutant Proteins / Q000502:physiology*; D049329:Nanostructures / Q000737:chemistry*; D044367:Phase Transition; D052899:Pore Forming Cytotoxic Proteins / Q000737:chemistry / Q000235:genetics; D016062:Porosity; D011489:Protein Denaturation; D058767:Protein Unfolding
chemical_list: D001427:Bacterial Toxins; D050505:Mutant Proteins; D052899:Pore Forming Cytotoxic Proteins; C032676:aerolysin