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Toward an Unified Description for Thermodynamics,
    Folding Kinetics, and Mutagenesis of Proteins”

* Speaker : Prof. Ik Soo Chang[Pusan National University]
* Place : Physics Seminar Room (Science Bldg, 3-201)
* Date & Time : Oct,해외 바카라 사이트16Fri)해외 바카라 사이트4:00 ~ 5:00 pm
 
Abstract
A multiscale-heterogeneous protein energy function was developed for the biophysical study of the
thermodynamics, folding kinetics, and mutagenesis of proteins. After hybridizing an해외 바카라 사이트atomic해외 바카라 사이트force-
field into a coarse-grained energy function to account for the specificity of a해외 바카라 사이트sequence해외 바카라 사이트of해외 바카라 사이트amino
acids even with the high structural homology, we constructed an exact free energy landscape of a
given protein and characterized its thermodynamics and folding-unfolding kinetics via해외 바카라 사이트a해외 바카라 사이트Chevron
plot based on solving exactly a master equation, which would enable us to pursue해외 바카라 사이트a해외 바카라 사이트mutagenesis
application. Our approach was applied successfully for resolving a controversy해외 바카라 사이트about해외 바카라 사이트the해외 바카라 사이트folding
mechanism of fast folding proteins.  

Recent experiments claiming that BBL protein follows a global downhill folding raised an important
controversy as to the folding mechanism of fast folding proteins. Under the global downhill folding
scenario not only proteins undergo a gradual folding, but also folding events along the continuous
folding pathway could be mapped out from the equilibrium denaturation experiment. Based on the
exact calculation using a free energy landscape, relaxation eigenmodes from해외 바카라 사이트a해외 바카라 사이트master해외 바카라 사이트equation,
and Monte Carlo simulation of an해외 바카라 사이트extended해외 바카라 사이트Munoz-Eaton해외 바카라 사이트model해외 바카라 사이트that해외 바카라 사이트incorporates해외 바카라 사이트multiscale-
heterogeneous pairwise-interactions between amino acids, here we show that the very nature of a
two-state cooperative transition such as a bimodal distribution from an exact free energy landscape
and biphasic relaxation kinetics do manifest in the thermodynamics해외 바카라 사이트and해외 바카라 사이트folding-unfolding해외 바카라 사이트kinetics
of BBL and peripheral subunit-binding domain (PSBD) homologue. Our results provide an unequivocal
resolution to the fundamental controversy related to해외 바카라 사이트the해외 바카라 사이트global해외 바카라 사이트downhill해외 바카라 사이트folding해외 바카라 사이트scheme,해외 바카라 사이트whose
applicability to other proteins should be critically re-examined.

Contact Person : Prof. Ki Bong Lee (054-279-2068, kibong@postech.ac.kr)

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