Single molecule studies of force-induced S2 site exposure in the mammalian Notch negative regulatory domain.

Notch signaling in metazoans is responsible for key cellular processes related to embryonic development and tissue homeostasis. Proteolitic cleavage of the S2 site within an extracellular NRR domain of Notch is a key early event in Notch signaling. We use single molecule force-extension (FX) atomic force microscopy (AFM) to study force-induced exposure of the S2 site in the NRR domain from mouse Notch 1.

Changes of protein stiffness during folding detect protein folding intermediates.

Single-molecule force-quench atomic force microscopy (FQ-AFM) is used to detect folding intermediates of a simple protein by detecting changes of molecular stiffness of the protein during its folding process. Those stiffness changes are obtained from shape and peaks of an autocorrelation of fluctuations in end-to-end length of the folding molecule. The results are supported by predictions of the equipartition theorem and agree with existing Langevin dynamics simulations of a simplified model of a protein folding.

Stiffness memory of EA.hy926 endothelial cells in response to chronic hyperglycemia.

Background: Glycemic memory of endothelial cells is an effect of long-lasting hyperglycemia and is a cause of various diabetics complications, that arises despite of the treatment targeted towards returning low glucose level in blood system. On the other hand, endothelial dysfunction, which is believed to be a main cause of cardiovascular complications, is exhibited in the changes of mechanical properties of cells. Although formation of the glycemic memory was widely investigated, its impact on the mechanical properties of endothelial cells has not been studied yet.