Singh Man, Chand Hema, Gupta K C
Chemistry Research Laboratory, Deshbandhu College, University of Delhi, New Delhi-110019, India.
Chem Biodivers. 2005 Jun;2(6):809-24. doi: 10.1002/cbdv.200590059.
Density (rho), apparent molar volume (V(phi)), and viscosity (eta) of 0.0010 to 0.0018% (w/v) of bovine serum albumin (BSA), egg albumin, and lysozyme in 0.0002, 0.0004, and 0.0008 M aqueous RbI and CsI, and (dodecyl)(trimethyl)ammonium bromide (DTAB) solutions were obtained. The experimental data were regressed against composition, and constants are used to elucidate the conformational changes in protein molecules. With salt concentration, the density of proteins is found to decrease, and the order of the effect of additives on density is observed as CsI > RbI > DTAB. The trend of apparent molar volume of proteins is found as BSA > egg-albumin > lysozyme for three additives. In general, eta values of BSA remain higher for all compositions of RbI than that of egg-albumin for CsI and DTAB. These orders of the data indicate the strength of intermolecular forces between proteins and salts, and are helpful for understanding the denaturation of proteins.
测定了0.0010至0.0018%（w/v）的牛血清白蛋白（BSA）、蛋清蛋白和溶菌酶在0.0002、0.0004和0.0008 M的碘化铷（RbI）和碘化铯（CsI）水溶液以及溴化（十二烷基）（三甲基）铵（DTAB）溶液中的密度（ρ）、表观摩尔体积（V(φ)）和粘度（η）。将实验数据与组成进行回归分析，并使用常数来阐明蛋白质分子的构象变化。随着盐浓度的增加，发现蛋白质的密度降低，并且观察到添加剂对密度影响的顺序为CsI > RbI > DTAB。对于三种添加剂，蛋白质表观摩尔体积的趋势为BSA > 蛋清蛋白 > 溶菌酶。一般来说，对于RbI的所有组成，BSA的η值都高于CsI和DTAB的蛋清蛋白的η值。这些数据顺序表明了蛋白质与盐之间分子间力的强度，有助于理解蛋白质的变性。
