ADSORPTION OF PROTEIN ONTO STAINLESS-STEEL SURFACES
ADSORPTION OF PROTEIN ONTO STAINLESS-STEEL SURFACES
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DOI：
10.1016/0922-338x(95)98168-k
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发表时间：
1995-01-01
期刊：
影响因子：
--
通讯作者：
NAGATA, K
中科院分区：
文献类型：
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作者：
FUKUZAKI, S;URANO, H;NAGATA, K
研究了无孔不锈钢颗粒对牛血清白蛋白（BSA）和明胶在不锈钢表面上的吸附随pH的变化规律。BSA和明胶的净电荷当量随着pH值从各自蛋白质的等电点（I.E.P，的）的差异的增加而增加，伴随着电荷诱导的分子膨胀。BSA和明胶自发吸附在带正电荷和负电荷的不锈钢表面上，即使蛋白质具有与不锈钢表面相同的电荷符号。吸附等温线类似于Langmuir型的饱和平台，构建BSA和明胶在pH值为3.2至8.0的范围内。平台值随pH值变化，在I. E. P.附近产生最大值。的BSA和明胶。计算每个BSA分子吸附在不锈钢表面上的饱和面积表明，蛋白质分子上的净电荷是决定蛋白质分子在吸附层中的堆积密度的关键因素。当离子强度从10（-3）增加到10（-1）时，BSA的吸附量显著增加，而明胶的吸附量在蛋白质的等电区略有下降。BSA在不锈钢表面上的吸附在高于50摄氏度的温度下显著增强，超过该温度BSA逐渐变性。另一方面，明胶的吸附量从40 ℃到80 ℃逐渐减少。结果表明，蛋白质在不锈钢-液体界面上的吸附行为主要取决于溶质蛋白质分子在环境条件变化下的性质，而不是不锈钢表面的性质。
The adsorption of bovine serum albumin (BSA) and gelatin onto stainless-steel surfaces was studied as a function of pH, using nonporous stainless-steel particles. The net charge equivalents of BSA and gelatin increased with increasing difference in pH values from the isoelectric points (I.E.P,'s) of the respective proteins, accompanied by charge-induced molecular expansion. BSA and gelatin adsorbed spontaneously on positively and negatively charged stainless-steel surfaces, even though the proteins had the same sign of charge as that of the stainless-steel surfaces. Adsorption isotherms similar to Langmuir-type ones with saturation plateaus were constructed for BSA and gelatin in a pH range of 3.2 to 8.0. The plateau values varied with pH, giving maxima around the I.E.P.'s of BSA and gelatin. Calculation of saturation area per BSA molecule adsorbed on stainless-steel surfaces suggests that the net charge on protein molecules is a key factor determining the packing density of protein molecules in the adsorbed layer. An increase in ionic strength from 10(-3) to 10(-1) resulted in a significant increase in the adsorbed amount of BSA but a slight decrease in that of gelatin in the isoelectric regions of the proteins. The adsorption of BSA onto stainless-steel surfaces was markedly enhanced at temperatures above 50 degrees C, beyond which BSA was progressively denatured. On the other hand, the adsorbed amount of gelatin decreased gradually from 40 to 80 degrees C. It is concluded that the adsorption behavior of proteins at stainless steel-liquid interfaces was mainly governed by the properties of solute protein molecules under changing environmental conditions, rather than by the nature of the stainless-steel surfaces.