tailieunhanh - Báo cáo sinh học: "The effects of lipids on channel function"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: The effects of lipids on channel function. | Journal of Biology Minireview The effects of lipids on channel function Anthony G Lee Address School of Biological Sciences University of Southampton Southampton SO16 7PX UK. Email agl@ Abstract Anionic lipids affect the function of many channels including connexins as shown in a recent report in BMC Biology. These effects might follow from direct binding of the anionic lipids to the channels. water-soluble protein. Given that the effects of anionic lipid on channel function are generally seen only at high concentrations of the anionic lipid it is likely that the a Lipids affect channel function Many membrane channels for proper function require the presence of particular species of lipid in the surrounding membrane. In a recent paper in BMC Biology Locke and Harris 1 provide an example of this they showed that connexin channels are inactive in a membrane composed of just the zwitterionic lipid phosphatidylcholine PC but become active in the presence of the anionic lipid phosphatidylserine PS for lipid structures see Figure 1 . The full effect of PS is seen only when 60 or more of the lipid is PS. The effect is not structurally specific other anionic lipids such as phosphatidic acid PA and phosphatidylinositol PI have the same effect as PS. Similar observations have been made with other channels. For example the probability that the potassium channel KcsA is open is very low in bilayers of PC alone but increases with increasing anionic lipid content 2 the functions of inward rectifying potassium channels are modulated by PIs 3 and the presence of anionic lipid increases the rate of flux of small molecules through the mechanosensitive channel MscL 4 . Lipid binding to channels How are the effects of anionic lipid on channel function to be understood In some cases the interaction of lipid with a membrane protein is highly specific. For example a single molecule of the anionic lipid phosphatidylglycerol is seen in the X-ray crystal structure of the .