NalP: Difference between revisions

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Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

Chris Casey, Michal Harel, Jaime Prilusky, Alexander Berchansky, Joel L. Sussman

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 In order to test the function of the alpha helix within the domain a test was done in order to compare results of uptake within the domain with alpha helix and without the helix. An easy way to test this was a antibiotic assay. By isolating colonies strictly of gram negative bacteria with the alpha helix, NalPβ, and isolating colonies strictly of gram negative bacteria without the alpha helix, NalPβΔhelix, they could plate these separately. From there it was possible to compare susceptibility to antibiotics by placing the small circular tabs of antibiotics on the plate and measuring the difference in how effect the antibiotics was in penetrating the cell. The more penetration would show less growth inhibition or more sensitivity to the antibiotics. When the alpha helix was removed there was much more sensitivity to antibiotics showing that the removal of it leads to a more open pore.
+== Protein Transportation Mechanism ==
+http://www.ncbi.nlm.nih.gov/pmc/articles/PMC381419/bin/7600148f4.jpg
+Interesting questions were raised on how the alpha helix in the center if the beta barrel effected the mechanism of protein transportation out of the cell. The first step into understanding what shapes of proteins can move though the pore was figured by trying to move a disulfide bind through the pore. This was unsuccessful and led to part of the understanding that the only way that proteins can move though this pore was by being completely unfolded. Yet once inside of the extracellular material the protein much be folded. Knowing these tow crucial pieces of data it was clear that as the protein passes through the pore it is folded, and due to the c-terminal end's placement on the periplasm side of the pore it was highly unlikely that was the participating portion that effected the change in conformation of the protein as it passes through. Oppositely the n-terminal side of the pore lies on the alpha helix facing the extracellular matter placing it in prime location the change the conformation of the passing protein. Another possible place where interaction could occur between the passing protein and the pore would be at a large hairpin loop that is on the extracellular side of the pore. This would also provide a prime placement for initiation of protein folding.