Single-molecule protein unfolding in solid state nanopores.

ABSTRACT: We use single silicon nitride nanopores to study folded, partially folded, and unfolded single proteins by measuring their excluded volumes. The DNA-calibrated translocation signals of beta-lactoglobulin and histidine-containing phosphocarrier protein match quantitatively with that predicted by a simple sum of the partial volumes of the amino acids in the polypeptide segment inside the pore when translocation stalls due to the primary charge sequence. Our analysis suggests that the majority of the protein molecules were linear or looped during translocation and that the electrical forces present under physiologically relevant potentials can unfold proteins. Our results show that the nanopore translocation signals are sensitive enough to distinguish the folding state of a protein and distin

SUBMITTER: Talaga DS 

PROVIDER: S-EPMC2717167 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature