Denaturation of proteins by SDS and tetraalkylammonium dodecyl sulfates.
Denaturation of proteins by SDS and tetraalkylammonium dodecyl sulfates.
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DOI：
10.1021/la201832d
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发表时间：
2011-09-20
期刊：
影响因子：
--
通讯作者：
Whitesides GM
中科院分区：
文献类型：
--
作者：
Lee A;Tang SK;Mace CR;Whitesides GM
采用毛细管电泳（CE）研究了在阴离子表面活性剂十二烷基硫酸盐（DS−）存在下，不同阳离子（C+; C+ = Na+和四烷基铵，NR 4+，其中R = Me，Et，Pr，Bu）对牛碳酸酐酶II（BCA）变性速率的影响。对BCA在Na+DS−和NR 4 +DS−（在Tris-Gly缓冲液中）溶液中变性的分析表明，变性BCA与DS−（BCAD-DS−n，sat）形成复合物的速率是不可区分的，并且在临界胶束浓度（cmc）以下与阳离子无关，在cmc以上与DS−的总浓度无关。当C+DS−的浓度高于cmc时，BCA的变性速率取决于阳离子;速率降低了104倍以上，顺序为Na+ ~ NMe 4 + > NEt 4 + > NPr 4 + > NBu 4 + --与cmc值的顺序相同（在Tris-Gly缓冲液中，从Na+DS−的4.0 mM降低到NBu 4 +DS−的0.9 mM）。cmc值与BCAD-DS−n，sat形成速率之间的关系表明，BCA的变性动力学涉及这种蛋白质与单体DS−的缔合，而不是与（C+DS−）n的胶束缔合。对其他7种蛋白质（α-乳白蛋白、β-乳球蛋白A、β-乳球蛋白B、羧肽酶B、肌酸磷酸激酶、肌红蛋白和泛素）的不太详细的研究表明，在BCA中观察到的Na+DS−和NR 4 +DS−之间的差异并不普遍。相反，NR 4+对DS-与这些蛋白质结合的影响取决于蛋白质。阳离子的选择有助于变性蛋白质和DS-聚集体的性质（包括组成、电泳迁移率和在双水相系统中的分配行为）。这些结果表明，NR 4 +DS−的行为随着R的变化而变化，可以用于分析和分离蛋白质混合物的方法。
This paper describes the use of capillary electrophoresis (CE) to examine the influence of different cations (C+; C+ = Na+ and tetra-n-alkylammonium, NR4 +, where R = Me, Et, Pr, Bu) on the rates of denaturation of bovine carbonic anhydrase II (BCA) in the presence of the anionic surfactant dodecylsulfate (DS−). Analysis of the denaturation of BCA in solutions of Na+DS− and NR4 +DS− (in Tris-Gly buffer) indicated that the rates of formation of complexes of denatured BCA with DS− (BCAD-DS−n,sat) are indistinguishable and independent of the cation below the critical micellar concentration (cmc), and independent of the total concentration of DS− above the cmc. At concentrations of C+DS− above the cmc, BCA denatured with rates that depended on the cation; the rates decreased by a factor > 104, in the order Na+ ~ NMe4 + > NEt4 + > NPr4 + > NBu4 + – the same order as the values of cmc (which decrease from 4.0 mM for Na+DS− to 0.9 mM for NBu4 +DS− in Tris-Gly buffer). The relationship between values of cmc and rates of formation of BCAD-DS−n,sat suggested that the kinetics of denaturation of BCA involve the association of this protein with monomeric DS−, rather than with micelles of (C+DS−)n. A less-detailed survey of seven other proteins (α-lactalbumin, β-lactoglobulin A, β-lactoglobulin B, carboxypeptidase B, creatine phosphokinase, myoglobin, and ubiquitin) showed that the difference between Na+DS− and NR4 +DS− observed with BCA was not general. Instead, the influence of NR4 + on the association of DS− with these proteins depended on the protein. The selection of cation contributed to the properties (including composition, electrophoretic mobility, and partitioning behavior in aqueous two-phase systems) of aggregates of denatured protein and DS−. These results suggest that variation in the behavior of NR4 +DS− with changes in R may be exploited in methods for analyzing and separating mixtures of proteins.
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影响因子：
15
作者：
Carbeck, JD;Colton, IJ;Whitesides, GM
通讯作者：
Whitesides, GM
影响因子：
3.4
作者：
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影响因子：
3.3
作者：
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3.3
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影响因子：
2.9
作者：
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通讯作者：
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