[2016 Fall Life Sciences & IBB Regular Seminar]


▶Subject: Unusual protein-protein interaction that involves coupled unfolding and binding

▶Speaker: Prof. Jeong-Yong Suh

(Department of Agricultural Biotechnology, Seoul National University)



▶Date: 4:30PM/Sept. 23(Fri.)/2016

▶Place: Auditorium(1F), Postech Biotech Center

*Abctract
Protein-protein interactions often involve conformation changes to present complementary interaction surfaces for optimal binding. It is well known that disordered proteins can adopt well-defined folds when they bind to their partner proteins. Here, an unusual binding mode that couples protein unfolding and binding is presented. Aptide (APT), a 26-aa peptide based on a tryptophan zipper fold, recognizes diverse molecular targets with high affinity and specificity. The solution structure of an APT specifically bound to fibronectin extradomain B (EDB), a prominent marker of tumor angiogenesis, illustrates a unique interaction of coupled unfolding and binding. Specifically, APT binding is accompanied by unfolding of the C-terminal  strand of EDB, permitting APT to interact with fresh-exposed hydrophobic interior surfaces of EDB. The -hairpin scaffold of APT drives the interaction by a -strand displacement mechanism, such that an intramolecular  sheet is replaced by an intermolecular  sheet. Binding thermodynamics reveals an enthalpic and entropic balance during the unfolding and binding. Unfolding of EDB perturbs the tight domain-domain association between EDB and FN8 of fibronectin, highlighting its potential application in vivo.




▶Inquiry: Prof. Cheol-Sang Hwang (279-2355)


* This seminar will be given in English.
please refrain from taking photos during seminars. *