@article {1350,
	title = {Single molecule force spectroscopy reveals a weakly populated microstate of the FnIII domains of tenascin},
	journal = {Journal of Molecular Biology},
	volume = {361},
	number = {2},
	year = {2006},
	note = {ISI Document Delivery No.: 074WPTimes Cited: 8Cited Reference Count: 48Cao, Y. Li, Hongbin},
	month = {Aug},
	pages = {372-381},
	type = {Article},
	abstract = {The native states of proteins exist as an ensemble of conformationally similar microstates. The fluctuations among different microstates are of great importance for the functions and structural stability of proteins. Here, we demonstrate that single molecule atomic force microscopy (AFM) can be used to directly probe the existence of multiple folded microstates. We used the AFM to repeatedly stretch and relax a recombinant tenascin fragment TNfnALL to allow the fibronectin type III (FnIII) domains to undergo repeated unfolding/refolding cycles. In addition to the native state, we discovered that some FnIII domains can refold from the unfolded state into a previously unrecognized microstate, N* state. This novel state is conformationally similar to the native state, but mechanically less stable. The native state unfolds at similar to 120 pN, while the N* state unfolds at similar to 50 pN. These two distinct populations of microstates constitute the ensemble of the folded states for some FnIII domains. An unfolded FnIII domain can fold into either one of the two microstates via two distinct folding routes. These results reveal the dynamic and heterogeneous picture of the folded ensemble for some FnIII domains of tenascin, which may carry important implications for the mechanical functions of tenascins in vivo. (c) 2006 Elsevier Ltd. All rights reserved.},
	keywords = {DYNAMICS, fluctuations, FnIII domains, HYDROGEN-EXCHANGE, IMMUNOGLOBULIN, MECHANICAL STABILITY, mechanical unfolding, microscopy, MODULES, PROTEIN-STRUCTURE, scanning probe, single-molecule force spectroscopy, tenascin, TITIN, UNFOLDING PATHWAYS},
	isbn = {0022-2836},
	url = {<Go to ISI>://000239842800014},
	author = {Cao, Y. and Li, H. B.}
}
@article {1621,
	title = {The unfolding and folding dynamics of TNfnALL probed by single molecule force-ramp spectroscopy},
	journal = {Polymer},
	volume = {47},
	number = {7},
	year = {2006},
	note = {ISI Document Delivery No.: 030JETimes Cited: 10Cited Reference Count: 53},
	month = {Mar},
	pages = {2548-2554},
	type = {Article},
	abstract = {Tenascin, an important extracellular matrix protein, is subject to stretching force under physiological conditions and plays important roles in regulating the cell-matrix interactions. Using the recently developed single molecule force-ramp spectroscopy, we investigated the unfolding-folding kinetics of a recombinant tenascin fragment TNfnALL. Our results showed that all the 15 FnIII domains in TNfnALL have similar spontaneous unfolding rate constant at zero force, but show great difference in their folding rate constants. Our results demonstrated that single molecule force-ramp spectroscopy is a powerful tool for accurate determination of the kinetic parameters that characterize the unfolding and folding reactions. We anticipate that single molecule force-ramp spectroscopy will become a versatile addition to the single molecule manipulation tool box and greatly expand the scope of single molecule force spectroscopy. (c) 2006 Elsevier Ltd. All rights reserved.},
	keywords = {ADHESION, DOMAIN, EXPRESSION, III, IMMUNOGLOBULIN, MATRIX PROTEINS, MECHANICAL STABILITY, microscopy, MUSCLE PROTEIN TITIN, tenascin, UBIQUITIN},
	isbn = {0032-3861},
	url = {<Go to ISI>://000236629900037},
	author = {Wang, M. J. and Cao, Y. and Li, H. B.}
}
