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Prof. Igal Szleifer
Biomedical Engineering, Chemical and Biological Engineering, Chemistry of Life Processes Institute
and McCormick School of Engineering and Applied Science.
Northwestern University, Evanston, IL, USA.
Martes 23 de Agosto, 14:30hs.
Aula Magna de la Fa.M.A.F, Ciudad Universitaria.
Resumen:
In this presentation I will describe recent related to the theoretical description of two types of polymeric systems that help in the understanding of properties of cell nuclei. The first problem relates to the role that macromolecular crowding plays in chromatin compaction. We have developed a method to determine the effective interactions between model chromatin beads in the presence of protein crowders, e.g. transcription factors. We use the effective interactions to simulate large chromatin fibers and demonstrate that the depletion interactions mediated by the proteins result in a non‐monotonic variation of the compaction with crowder concentration. We will discuss the role of how chromatin is compacted in the ability of the transcription factors to access the chromatin and how these results are important to the understanding of experimental observations on cancer. The second problem relates to the structure of nuclear pore complexes. In this case hourglass shaped pores are coated with disordered proteins. These proteins control the
traffic of molecules from the cytoplasm to the cell nuclei (and vice versa). We have studied the role of the pore geometry, polymer coating and environment on the structure and transport behavior of
polymer coated nanopores. In particular, we will discuss the role of pH and the coupling between chemical equilibrium and molecular structure in determining the behavior of the pore. We will show
that it is imperative to consider the local charge regulation by pH and we will discuss how geometry plays a key role in determining the structure of the coated molecules and the transport properties through the pores.
Seminario del GTMC, Fa.M.A.F – UNC
Contacto: igalsz@northwestern.edu
