Jirgensons B
Biochim Biophys Acta. 1978 May 24;534(1):123-31. doi: 10.1016/0005-2795(78)90482-8.
The effects of 25 to 75 volume-% ethanol on conformation of human serum alpha1-acid glycoprotein, human serum alpha1-antitrypsin, pancreatic deoxyribonuclease I, porcine pepsinogen, the "Kunitz" trypsin inhibitor from soybeans, and oxidized as well as reduced and S-carboxymethylated ribonucleases were tested by the circular dichroism (CD) probe. It was found that 25 volume-% ethanol had a slight effect, whereas 50--75 vol.-% alcohol significantly altered the conformation. The tertiary structure was perturbed and the polypeptide main chain was reorganized into new conformations of higher helix and beta-structure contents than in the native state. Comparison of the various proteins showed that the degree of reorganization depended chiefly on the cross-linking of the main chain by disulfide bridges. While the unfolded ribonucleases were refolded by 25 vol.-% ethanol into ordered conformations, the native ribonuclease and alpha1-antitrypsin was more sensitive to 25 vol.-% ethanol than the conformation of alpha1-acid glycoprotein, pepsinogen, and soybean trypsin inhibitor. Almost complete restoration of the native conformation was achieved by diluting the alcohol-containing solutions with water or by dialysis against water or buffer solutions. However, the renaturation depended on the time of contact with alcohol and on the temperature at which the alcohol-containing solutions were kept.
通过圆二色性（CD）探针测试了体积分数为25%至75%的乙醇对人血清α1-酸性糖蛋白、人血清α1-抗胰蛋白酶、胰腺脱氧核糖核酸酶I、猪胃蛋白酶原、大豆“Kunitz”胰蛋白酶抑制剂以及氧化型、还原型和S-羧甲基化核糖核酸酶构象的影响。结果发现，体积分数为25%的乙醇影响轻微，而体积分数为50%至75%的乙醇则显著改变构象。三级结构受到扰动，多肽主链重新组织成比天然状态下具有更高螺旋和β-结构含量的新构象。对各种蛋白质的比较表明，重组程度主要取决于主链通过二硫键的交联情况。虽然未折叠的核糖核酸酶可被体积分数为25%的乙醇重折叠成有序构象，但天然核糖核酸酶和α1-抗胰蛋白酶对体积分数为25%的乙醇比α1-酸性糖蛋白、胃蛋白酶原和大豆胰蛋白酶抑制剂的构象更敏感。通过用水稀释含醇溶液或对水或缓冲溶液进行透析，几乎可完全恢复天然构象。然而，复性取决于与乙醇接触的时间以及含醇溶液保存的温度。
