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Báo cáo y học: "Flexible peptides and cytoplasmic gels"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Flexible peptides and cytoplasmic gels. | Opinion Flexible peptides and cytoplasmic gels Dennis Bray Address Department of Anatomy University of Cambridge Cambridge CB2 3DY UK. E-mail dbi0009@cam.ac.uk Published 28 February 2005 Genome Biology 2005 6 106 The electronic version of this article is the complete one and can be found online at http genomebiology.com 2005 6 3 l06 2005 BioMed Central Ltd Abstract Recent progress in predicting protein structures has revealed a surprising abundance of proteins that are significantly unfolded under physiological conditions. Unstructured flexible polypeptides are likely to be functionally important and may cause local cytoplasmic regions to become gel-like. In his 2001 book Cells Gels and the Engines of Life 1 Gerald Pollack gives a highly entertaining and accessible account of cell biology from the standpoint of polymer chemistry. The cytoplasm is indubitably gel-like he says so we must expect it to have similar properties to other non-living gels cells should swell and shrink depending on ionic conditions and undergo dramatic phase changes associated with sol-to-gel transitions. In the broad sweep of published literature on living cells there is indeed abundant support for this thesis and Pollack is not the first to advance such views. But probably no one else has made the argument so forcefully or taken it so far. Too far perhaps for when Pollack challenges the role of the phospholipid bilayer as a permeability barrier or offers new and dramatically simplified explanations for such well-understood phenomena as action potentials muscle contraction and mitosis he leaves most professional biologists behind 2 . This is unfortunate since there is much we do not know about the physical conditions existing in the cytoplasm and here Pollack says much that is relevant - one should not throw out the baby with the bath water. Cytoplasmic gels are associated in my mind with long flexible polymers which is why I thought about Pollack s book recently when reading about .