Stepwise unfolding of titin under force-clamp atomic force microscopy.

  title={Stepwise unfolding of titin under force-clamp atomic force microscopy.},
  author={Andr{\'e}s F. Oberhauser and Paul K. Hansma and Mariano Carri{\'o}n-V{\'a}zquez and J. M. Fern{\'a}ndez},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  volume={98 2},
Here we demonstrate the implementation of a single-molecule force clamp adapted for use with an atomic force microscope. We show that under force-clamp conditions, an engineered titin protein elongates in steps because of the unfolding of its modules and that the waiting times to unfold are exponentially distributed. Force-clamp measurements directly measure the force dependence of the unfolding probability and readily captures the different mechanical stability of the I27 and I28 modules of… CONTINUE READING