HYDROPHOBIC BOND IN MICELLAR SYSTEMS . EFFECTS OF VARIOUS ADDITIVES ON STABILITY OF MICELLES OF SODIUM DODECYL SULFATE AND OF N-DODECYLTRIMETHYLAMMONIUM BROMIDE
HYDROPHOBIC BOND IN MICELLAR SYSTEMS . EFFECTS OF VARIOUS ADDITIVES ON STABILITY OF MICELLES OF SODIUM DODECYL SULFATE AND OF N-DODECYLTRIMETHYLAMMONIUM BROMIDE
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DOI：
10.1021/j100869a031
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发表时间：
1967-01-01
影响因子：
--
通讯作者：
HOLTZER, A
中科院分区：
文献类型：
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作者：
EMERSON, MF;HOLTZER, A
本文报道了十二烷基硫酸钠(十二烷基硫酸钠)和十二烷基三甲基溴化铵(DTAB)在多种含蛋白质变性剂或密切相关化合物的水溶液中以及在D20中在不同温度下的电导临界胶束浓度(CMC)的测定结果。在给定的介质中观察到的CMC与温度的关系提供了洗涤剂分子加入该介质中最可能大小的胶束时的标准热变和标准熵变化：讨论了这些总的热项和熵项对胶束稳定性的相对贡献。研究还表明，目前的实验技术不足以评估电性和疏水性对这些热力学参数的贡献。定性上，可以观察到添加剂的疏水性和其打破胶束的能力之间的相关性，但只能通过将比较限制在一组类似的化合物中，并考虑到某些化合物可能穿透胶束的可能性。提出了区分渗透性添加剂和非渗透性添加剂的简单实验准则。即使是这些有限的、定性的相关性应用到蛋白质中疏水键的情况，也必须相当谨慎，这一点很清楚。
The results of measurements of the (conductivity) critical micelle concentrations (cmc) of sodium dodecyl sulfate (SDS) and n-dodecyltrimethylammonium bromide (DTAB) at several temperatures in a wide variety of aqueous mediacontaining protein denaturants or closely related compounds and in D20 are presented. The observed temperature dependence of the cmc in a given medium has been shown to provide the standard enthalpy and entropy changes accompanying addition of a detergent molecule to a micelle of the most probable size in that medium: the relative contributions of these over-all enthalpic and entropic terms to the micelle stability are discussed. It is also shown that present experimental techniques are inadequate to allow assessment of the electrical and hydro-phobic contributions to these thermodynamic parameters. Qualitatively, correlations are observed between thehydrophobic nature of the additive and its micelle-breaking power, but only by confining the comparisons within a group of similar compounds and by allowing for the possibilitythat some compounds may penetrate the micelle. Simple experimental criteria are developed for distinguishing such penetrating additives from non-penetrating ones. Application of even these limited, qualitative correlations to the case of hydrophobic bonds in proteins, it is made clear, will have to be done with considerable caution.