Interaction of human serum albumin with membranes containing polymer-grafted lipids: spin-label ESR studies in the mushroom and brush regimes
Interaction of human serum albumin with membranes containing polymer-grafted lipids: spin-label ESR studies in the mushroom and brush regimes
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DOI：
10.1016/s0005-2736(02)00458-3
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发表时间：
2002-08-19
影响因子：
3.4
通讯作者：
Sportelli, L
中科院分区：
文献类型：
--
作者：
Bartucci, R;Pantusa, M;Sportelli, L
研究了聚乙二醇接枝二棕榈酰磷脂酰乙醇胺（PEG-DPPE）双层膜对人血清白蛋白（HSA）的吸附行为，考察了分子量和分子头基大小对吸附的影响。在没有蛋白质的情况下，从低密度蘑菇政权的高密度刷政权的聚合物-脂质含量的转换检测的变化，ESR外部超精细分裂，2A（最大值），链自旋标记的磷脂酰胆碱在凝胶相膜。2A的值在蘑菇状区域中保持恒定，但在进入刷状区域时减小。如理论上预期的，对于平均PEG分子量为350、2000和5000 Da的PEG-DPPE，两种方案之间的转化发生在摩尔分数X-PEG（m -> h）分别接近0.04、0.01-0.02和0.005-0.01时。检测到HSA对DPPC膜的吸附作为凝胶相中的自旋标记2.4（最大）超精细分裂的减少。饱和度是在蛋白质/脂质比约为0.5时获得的。1：1 w/w。在聚合物接枝的脂质的存在下，HSA吸附到DPPC膜仅在蘑菇政权，无论聚合物的长度。在刷制度，自旋标记值2A（最大值）在蛋白质的存在下是不变的。即使在蘑菇政权，蛋白质吸附逐渐成为强烈衰减的聚合物脂质所施加的空间稳定的结果。这些结果与理论估计的接枝聚合物在刷状和蘑菇状政权，分别施加的侧压力一致。(C)2002 Elsevier Science B. V.保留所有权利。
The adsorption of human serum albumin (HSA) to dipalmitoyl phosphatidylcholine (DPPC) bilayer membranes containing poly(ethylene glycol)-grafted dipalmitoyl phosphatidylethanolamine (PEG-DPPE) was studied as a function of content and headgroup size of the polymer lipid. In the absence of protein, conversion from the low-density mushroom regime to the high-density brush regime of polymer-lipid content is detected by the change in ESR outer hyperfine splitting, 2A(max), of chain spin-labelled phosphatidylcholine in gel-phase membranes. The values of 2A,; remain constant in the mushroom regime, but decrease on entering the brush regime. Conversion between the two regimes occurs at mole fractions X-PEG(m --> h) approximate to 0.04, 0.01-0.02 and 0.005-0.01 for PEG-DPPE with mean PEG molecular masses of 350, 2000 and 5000 Da, respectively, as expected theoretically. Adsorption of HSA to DPPC membranes is detected as a decrease of the spin label 2.4(max) hyperfine splitting in the gel phase. Saturation is obtained at a protein/lipid ratio of ca. 1:1 w/w. In the presence of polymer-grafted lipids, HSA adsorbs to DPPC membranes only in the mushroom regime, irrespective of polymer length. In the brush regime, the spin-label values of 2A(max) are unchanged in the presence of protein. Even in the mushroom regime, protein adsorption progressively becomes strongly attenuated as a result of the steric stabilization exerted by the polymer lipid. These results are in agreement with theoretical estimates of the lateral pressure exerted by the grafted polymer in the brush and mushroom regimes, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.