Atomic force microscopy reveals parallel mechanical unfolding pathways of T4 lysozyme: evidence for a kinetic partitioning mechanism.

ABSTRACT: Kinetic partitioning is predicted to be a general mechanism for proteins to fold into their well defined native three-dimensional structure from unfolded states following multiple folding pathways. However, experimental evidence supporting this mechanism is still limited. By using single-molecule atomic force microscopy, here we report experimental evidence supporting the kinetic partitioning mechanism for mechanical unfolding of T4 lysozyme, a small protein composed of two subdomains. We observed that on stretching from its N and C termini, T4 lysozyme unfolds by multiple distinct unfolding pathways: the majority of T4 lysozymes unfold in an all-or-none fashion by overcoming a dominant unfolding kinetic barrier; and a small fraction of T4 lysozymes unfold in three-state fashion involving

SUBMITTER: Peng Q 

PROVIDER: S-EPMC2538854 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature