@article {2695,
	title = {Modulating the Mechanical Stability of Extracellular Matrix Protein Tenascin-C in a Controlled and Reversible Fashion},
	journal = {Journal of Molecular Biology},
	volume = {390},
	number = {4},
	year = {2009},
	note = {ISI Document Delivery No.: 477KYTimes Cited: 2Cited Reference Count: 45Zhuang, Shulin Peng, Qing Cao, Yi Li, Hongbin},
	month = {Jul},
	pages = {820-829},
	type = {Article},
	abstract = {Stretching force can induce conformational changes of proteins and is believed to be an important biological signal in the mechanotransduction network. Tenascin-C is a large extracellular matrix protein and is subject to stretching force under its physiological condition. Regulating the mechanical properties of the fibronectin type III domains of tenascin-C will alter its response to mechanical stretching force and thus may provide the possibility of regulating the biological activities of tenascin-C in living cells. However, tuning the mechanical stability of proteins in a rational and systematic fashion remains challenging. Using the third fibronectin type III domain (TNfn3) of tenascin-C as a model system, here we report a successful engineering of a mechanically stronger extracellular matrix protein via engineered metal chelation. Combining steered molecular dynamics simulations, protein engineering and single-molecule atomic force microscopy, we have rationally engineered a bihistidine-based metal chelation site into TNfn3. We used its metal chelation capability to selectively increase the unfolding energy barrier for the rate-limiting step during the mechanical unfolding of TNfn3. The resultant TNfn3 mutant exhibits enhanced mechanical stability. Using a stronger metal chelator, one can convert TNfn3 back to a state of lower mechanical stability. This is the first step toward engineering extracellular matrix proteins with defined mechanical properties, which can be modulated reversibly by external stimuli, and will provide the possibility of using external stimuli to regulate the biological functions of extracellular matrix proteins. (C) 2009 Elsevier Ltd. All rights reserved.},
	keywords = {DYNAMICS, ELASTICITY, ENGINEERING PROTEINS, FNIII DOMAIN, FRAGMENTS, MECHANICAL STABILITY, mechanical unfolding, microscopy, MOLECULE FORCE SPECTROSCOPY, MUSCLE, rational design, recombination, SINGLE PROTEIN, single-molecule force spectroscopy, tenascin},
	isbn = {0022-2836},
	url = {<Go to ISI>://000268519200019},
	author = {Zhuang, S. L. and Peng, Q. and Cao, Y. and Li, H. B.}
}
@article {2247,
	title = {Stabilization provided by neighboring strands is critical for the mechanical stability of proteins},
	journal = {Biophysical Journal},
	volume = {95},
	number = {8},
	year = {2008},
	note = {ISI Document Delivery No.: 352NMTimes Cited: 5Cited Reference Count: 37Sharma, Deepak Feng, Gang Khor, Dingyue Genchev, Georgi Z. Lu, Hui Li, Hongbin},
	month = {Oct},
	pages = {3935-3942},
	type = {Article},
	abstract = {Single-molecule force spectroscopy studies and steered molecular dynamics simulations have revealed that protein topology and pulling geometry play important roles in determining the mechanical stability of proteins. Most studies have focused on local interactions that are associated with the force-bearing beta-strands. Interactions mediated by neighboring strands are often overlooked. Here we use Top7 and barstar as model systems to illustrate the critical importance of the stabilization effect provided by neighboring beta-strands on the mechanical stability. Using single-molecule atomic force microscopy, we showed that Top7 and barstar, which have similar topology in their force-bearing region, exhibit vastly different mechanical-stability characteristics. Top7 is mechanically stable and unfolds at similar to 150 pN, whereas barstar is mechanically labile and unfolds largely below 50 pN. Steered molecular dynamics simulations revealed that stretching force peels one force-bearing strand away from barstar to trigger unfolding, whereas Top7 unfolds via a substructure-sliding mechanism. This previously overlooked stabilization effect from neighboring beta-strands is likely to be a general mechanism in protein mechanics and can serve as a guideline for the de novo design of proteins with significant mechanical stability and novel protein topology.},
	keywords = {BARSTAR, DYNAMICS SIMULATIONS, IMMUNOGLOBULIN DOMAINS, MICROSCOPE, MOLECULE FORCE SPECTROSCOPY, resistance, SINGLE PROTEIN, TITIN, TOPOLOGY, UBIQUITIN},
	isbn = {0006-3495},
	url = {<Go to ISI>://000259503900036},
	author = {Sharma, D. and Feng, G. and Khor, D. and Genchev, G. Z. and Lu, H. and Li, H. B.}
}
