Dynamic self-assembly of biomacromolecules probed at the single molecule and nanoscale level
소속 :
연사 : Prof.Joonil Seog(University of Maryland, College Park)
일시 : 2011-11-23 09:00 ~
장소 : 500동 목암홀
일 시 : 2011년 11월 23일, 4:00 PM
장 소 : 500동 목암홀
-Abstract-
Single molecule studies have been very powerful in providing mechanistic insights on biomolecular machineries. The capability of monitoring time trajectories of a single molecule reveals not only the averaged properties from bulk ensemble measurements but also entire distribution of relevant properties with infrequent events. Using optical tweezers, unfolding and refolding process of cell adhesion molecule was studied at the single molecule level. The molecule exhibited stepwise multiple transitions in a specific order during unfolding processes, showing mechanical hierarchy in a single protein domain. In the force clamping experiment, three intermediate states were observed when the molecule hops between unfolded state and refolded state. The strong correlation between folding behavior and allosteric region was revealed. At the nanoscale level, dynamic self-assembly behaviors of silk-elastin-like protein (SELP) polymers were studied using atomic force microscopy. Peptide based nanofibers have great potential in building smart hierarchical structures due to their tunable structures at the single residue level and their ability to reconfigure themselves in response to environmental stimuli. We observed that pre-adsorbed silk-elastin-like protein polymers self-assemble into nanofibers through conformational changes on a mica substrate. Furthermore, we demonstrate that the rate of self-assembly was significantly enhanced by applying a nanomechanical stimulus using atomic force microscopy. The orientation of the newly grown nanofibers was mostly perpendicular to the scanning direction, implying that the new fiber assembly was locally activated with directional control. Our method provides a novel way to prepare nanofiber patterned substrates using a bottom-up approach.
장 소 : 500동 목암홀
-Abstract-
Single molecule studies have been very powerful in providing mechanistic insights on biomolecular machineries. The capability of monitoring time trajectories of a single molecule reveals not only the averaged properties from bulk ensemble measurements but also entire distribution of relevant properties with infrequent events. Using optical tweezers, unfolding and refolding process of cell adhesion molecule was studied at the single molecule level. The molecule exhibited stepwise multiple transitions in a specific order during unfolding processes, showing mechanical hierarchy in a single protein domain. In the force clamping experiment, three intermediate states were observed when the molecule hops between unfolded state and refolded state. The strong correlation between folding behavior and allosteric region was revealed. At the nanoscale level, dynamic self-assembly behaviors of silk-elastin-like protein (SELP) polymers were studied using atomic force microscopy. Peptide based nanofibers have great potential in building smart hierarchical structures due to their tunable structures at the single residue level and their ability to reconfigure themselves in response to environmental stimuli. We observed that pre-adsorbed silk-elastin-like protein polymers self-assemble into nanofibers through conformational changes on a mica substrate. Furthermore, we demonstrate that the rate of self-assembly was significantly enhanced by applying a nanomechanical stimulus using atomic force microscopy. The orientation of the newly grown nanofibers was mostly perpendicular to the scanning direction, implying that the new fiber assembly was locally activated with directional control. Our method provides a novel way to prepare nanofiber patterned substrates using a bottom-up approach.
