Temperature and chemical denaturant dependence of forced unfolding of titin I27.
Single-molecule force measurement opens a new door for investigating detailed biomolecular interactions and their thermodynamic properties by pulling molecules apart while monitoring the force exerted on them. Recent advances in the nonequilibrium work theorem allows one to determine the free-energy landscapes of these events. Such information is valuable for understanding processes such as protein and RNA folding and receptor-ligand binding. Here, we used force as a physical parameter under the traditional chemical and temperature denaturing environment to alter the protein folding energy landscape and compared the change in the unfolding free-energy barrier of the I27 domain of human cardiac titin. We found that the trends in protein unfolding free-energy barriers are consistent for single-molecule force measurements and bulk chemical and temperature studies. The results suggest that the information from single-molecule pulling experiments are meaningful and useful for understanding the mechanism of folding of titin I27.
Botello
Eric
E
Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA.
Harris
Nolan C
NC
Sargent
Jacob
J
Chen
Wei-Hung
WH
Lin
Kuan-Jiuh
KJ
Kiang
Ching-Hwa
CH
D064211:Connectin; D006801:Humans; D009124:Muscle Proteins / Q000737:chemistry*; D011489:Protein Denaturation; D017510:Protein Folding; D011494:Protein Kinases / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D013696:Temperature; D013816:Thermodynamics
D064211:Connectin; D009124:Muscle Proteins; C577285:TTN protein, human; D011494:Protein Kinases