21–26 Jun 2026
U. Ottawa - Learning Crossroads (CRX) Building
America/Toronto timezone
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Effects of macromolecular crowding on protein fold switching

23 Jun 2026, 14:45
30m
U. Ottawa - Learning Crossroads (CRX) Building

U. Ottawa - Learning Crossroads (CRX) Building

100 Louis-Pasteur Private, Ottawa, ON K1N 9N3
Oral (Non-Student) / Orale (non-étudiant(e)) Physics in Medicine and Biology / Physique en médecine et en biologie (DPMB-DPMB) (DPMB T2-11 | (DPMB)

Speaker

Prof. Stefan Wallin (Memorial University of Newfoundland)

Description

While most folded proteins adopt a single, conformationally homogeneous native state, a small but growing class of proteins is known to reversibly switch between two structurally distinct folds. These fold transitions are typically triggered by changes in the local environment, such as binding to a partner molecule or variations in salt concentration or temperature, and often enable new, unrelated biological functions. Understanding the physical mechanisms underlying such fold switching remains a major challenge. We have developed a structure-based coarse-grained model capable of simulating both the thermodynamics and kinetics of fold switching. In this talk, I will discuss its application to both the engineered fold switch GA/GB, driven by point mutations, and the natural metamorphic protein XCL1, which switches folds upon dimerization. Using this model, we probe universal features of fold-switching mechanisms, examine how macromolecular crowding reshapes the free-energy landscape and alters relative fold populations, and characterize structural changes in the unfolded state under conditions favoring the different folds.

Keyword-1 Computational
Keyword-2 Proteins
Keyword-3 Fold switching

Author

Prof. Stefan Wallin (Memorial University of Newfoundland)

Co-authors

Bahman Seifi Jegarkandi Mr Greg de Souza (Memorial University of Newfoundland) Saman Bazmi

Presentation materials

There are no materials yet.