Gerbanowski A, Malabat C, Rabiller C, Guéguen J
Institut National de Recherche Agronomique, Unité de Biochimie et Technologie des protéines, B.P. 71627, 44316 Nantes Cedex 03, France.
J Agric Food Chem. 1999 Dec;47(12):5218-26. doi: 10.1021/jf990226p.
Lysyl residues of rapeseed napin (2S) and cruciferin (12S) were acylated and sulfamidated by means of anhydrides and sulfonyl chlorides, respectively. The secondary and tertiary structures as well as the surface hydrophobicity of the modified proteins were studied using circular dichroism, intrinsic fluorescence, and binding of anilinonaphthalenesulfonic acid. The results showed clearly that grafting of hydrophobic chains induced different structural modifications and surface hydrophobicities on the monomeric (2S) and on the hexameric (12S) proteins. Thus, the original structure of the 2S modified protein seemed to be preserved. Therefore, the surface hydrophobicity increased proportionally with the number of groups grafted. Conversely, after modification, 12S was shown to be expanded. As a result, hydrophobic regions were exposed, leading to a much greater hydrophobization of the protein surface. Acylation and sulfamidation appeared, therefore, to be good methods to hydrophobize efficiently the surface of the two proteins and thus might probably induce new functional properties.
油菜籽napin（2S）和cruciferin（12S）的赖氨酰残基分别通过酸酐和磺酰氯进行酰化和氨磺酰化。使用圆二色性、内源荧光和苯胺萘磺酸结合研究了修饰蛋白的二级和三级结构以及表面疏水性。结果清楚地表明，疏水链的接枝在单体（2S）和六聚体（12S）蛋白上诱导了不同的结构修饰和表面疏水性。因此，2S修饰蛋白的原始结构似乎得以保留。因此，表面疏水性随接枝基团的数量成比例增加。相反，修饰后，12S显示出膨胀。结果，疏水区域暴露，导致蛋白表面的疏水性大大增加。因此，酰化和氨磺酰化似乎是有效疏水化这两种蛋白表面的良好方法，因此可能会诱导新的功能特性。
