Thermodynamic analysis of proteins adsorbed on silica particles: Electrostatic effects
Thermodynamic analysis of proteins adsorbed on silica particles: Electrostatic effects
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DOI：
10.1006/jcis.2001.7485
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发表时间：
2001-05-01
影响因子：
9.9
通讯作者：
Buijs, J
中科院分区：
文献类型：
--
作者：
Larsericsdotter, H;Oscarsson, S;Buijs, J
使用差示扫描量热法（DSC）和吸附等温线研究了对蛋白质吸附的静电效应。在三种浓度的阳离子下检查了溶液中和吸附到二氧化硅纳米颗粒上的溶菌酶、核糖核酸酶A（RNase）和α-乳白蛋白的热变性：10和100 mM的钠和100 mM的钠，其中加入了10 mM的钙。结果表明，离子强度对溶菌酶和RNA酶的吸附等温线有很大的影响，离子强度对吸附等温线的影响很大。在低离子强度下，两种蛋白质对二氧化硅颗粒具有高亲和力，并且吸附伴随着Δ H降低15-25%和T-m降低3-6 ℃，表明蛋白质的吸附状态是不稳定的。此外，观察到变性转变宽度的增加，表明表面结合蛋白质的更大构象异质性。在更高的离子强度，无论有和没有添加钙，没有显着的吸附诱导的变化Δ H观察到所有三种蛋白质。然而，钙的加入降低了吸附状态下溶菌酶和RNA酶的变性转变的宽度。(C)北京：科学出版社.
Electrostatic effects on protein adsorption were investigated using differential scanning calorimetry (DSC) and adsorption isotherms, The thermal denaturation of lysozyme, ribonuclease A (RNase), and alpha -lactalbumin in solution and adsorbed onto silica nanoparticles was examined at three concentrations of cations: 10 and 100 mM of sodium and 100 mM of sodium to which 10 mM of calcium was added. The parameters investigated were the denaturation enthalpy (DeltaH), the temperature at which the denaturation transition was half-completed (T-m), and the temperature range of the denaturation transition.For lysozyme and RNase, adsorption isotherms depend strongly on the ionic strength. At low ionic strength both proteins have a high affinity for the silica particles and adsorption is accompanied by a 15-25% reduction in DeltaH and a 3-6 degreesC decrease in T-m, indicating that the adsorbed state of the proteins is destabilized, Also, an increase in the width of the denaturation transition is observed, signifying a larger conformational heterogeneity of the surface bound proteins. At higher ionic strengths, both with and without the addition of calcium, no significant adsorption-induced alteration in DeltaH was observed for all three proteins. The addition of calcium, however, decreases the width of the denaturation transition for lysozyme and RNase in the adsorbed state. (C) 2001 Academic Press.