2P028 Structural analyses of FROUNT, the cytosolic regulator of chemokine signaling, and its chemokine receptor recognition(01B. Protein: Structure & Function,Poster)

Abstract

Force is increasingly recognized as an important element in controlling biological processes. Forces are able to deform native protein conformations leading to protein-specific effects. Here we demonstrate that the calcium-binding affinity of the actin-binding protein gelsolin domain G6 is enhanced by mechanical force. Using a recently developed single molecule-binding assay based on atomic force microscopy, we establish that the calcium-binding affinity of G6 increases exponentially with the applied force, up to the point of G6 unfolding. This implies that gelsolin will be activated at lower calcium ion levels when subjected to tensile forces and suggests a basis for enhanced cooperativity during multi-cation induced activation. 2P026 Direct observation of the multiple sliding modes of a tumor suppressor p53