RT Journal Article
SR Electronic
T1 Single-Molecule Lysozyme Dynamics Monitored by an Electronic Circuit
JF Science
JO Science
FD American Association for the Advancement of Science
SP 319
OP 324
DO 10.1126/science.1214824
VO 335
IS 6066
A1 Choi, Yongki
A1 Moody, Issa S.
A1 Sims, Patrick C.
A1 Hunt, Steven R.
A1 Corso, Brad L.
A1 Perez, Israel
A1 Weiss, Gregory A.
A1 Collins, Philip G.
YR 2012
UL http://science.sciencemag.org/content/335/6066/319.abstract
AB Tethering a single lysozyme molecule to a carbon nanotube field-effect transistor produced a stable, high-bandwidth transducer for protein motion. Electronic monitoring during 10-minute periods extended well beyond the limitations of fluorescence techniques to uncover dynamic disorder within a single molecule and establish lysozyme as a processive enzyme. On average, 100 chemical bonds are processively hydrolyzed, at 15-hertz rates, before lysozyme returns to its nonproductive, 330-hertz hinge motion. Statistical analysis differentiated single-step hinge closure from enzyme opening, which requires two steps. Seven independent time scales governing lysozyme’s activity were observed. The pH dependence of lysozyme activity arises not from changes to its processive kinetics but rather from increasing time spent in either nonproductive rapid motions or an inactive, closed conformation.