High Temperature Extends the Range of Size Discrimination of Nonionic Polymers by a Biological Nanopore.

We explore the effect of temperature on the interaction of polydisperse mixtures of nonionic poly(ethylene glycol) (PEG) polymers of different average molar masses with the biological nanopore α-hemolysin. In contrast with what has been previously observed with various nanopores and analytes, we find that, for PEGs larger than a threshold molar mass (2000 g/mol, PEG 2000), increasing temperature increases the duration of the PEG/nanopore interaction. In the case of PEG 3400 the duration increases by up to a factor of 100 when the temperature increases from 5 °C to 45 °C.

Evidence of unfolded protein translocation through a protein nanopore.

Protein nanopores are mainly used to study transport, unfolding, intrinsically disordered proteins, protein-pore interactions, and protein-ligand complexes. This single-molecule sensor for biomedical and biotechnological applications is promising but until now direct proof of protein translocation through a narrow channel is lacking. Here, we report the translocation of a chimera molecule through the aerolysin nanopore in the presence of a denaturing agent, guanidium chloride (1.

Polyelectrolyte entry and transport through an asymmetric alpha-hemolysin channel.

We study the entry and transport of a polyelectrolyte, dextran sulfate (DS), through an asymmetric alpha-hemolysin protein channel inserted into a planar lipid bilayer. We compare the dynamics of the DS chains as they enter the channel at the opposite stem or vestibule sides. Experiments are performed at the single-molecule level by using an electrical method.

Involvement of alphavbeta 3 integrin and disruption of endothelial fibronectin network during the adhesion of the human ovarian adenocarcinoma cell line IGROV1 on the human umbilical vein cell extracellular matrix.

Like the majority of tumor cells, ovarian cancer cell growth is critically dependent on their neovascularization. Adhesion molecules and cellular events that lead to ovarian tumor cell interactions with endothelial extracellular matrix surrounding the vasculature are poorly identified. To understand the role of alphavbeta3 integrin and its ligand fibronectin in this process, we used in vitro coculture models with IGROV1 human ovarian adenocarcinoma cell line and human umbilical vein endothelial cells (HUVEC).