Waniska R D, Kinsella J E
Int J Pept Protein Res. 1984 May;23(5):467-76. doi: 10.1111/j.1399-3011.1984.tb02747.x.
Maltosyl and glucosaminyl derivatives of beta-lactoglobulin (b-LG) were analyzed for their physicochemical properties: reduced viscosity, ultraviolet difference spectra, intrinsic fluorescence, hydrophobicity and circular dichroism. The viscosity of these derivatives increased as the mass of the carbohydrates covalently linked to b-LG increased. The ultraviolet difference spectra and the intrinsic fluorescence of these proteins revealed that the microenvironments of aromatic amino acid residues of b-LG were increasingly exposed to the surface of the protein as the extent of modification increased; and the polarity of these residues also increased as modification increased. The hydrophobicities of M-b-LG derivatives decreased as the extent of modification increased while the hydrophobicities of G-b-LG derivatives were relatively unchanged. The circular dichroic analysis of these proteins indicated that the order secondary structures of the extensively modified derivatives of b-LG were partially unfolded. Thus, the carbohydrates covalently linked to b-LG altered many physiochemical properties. These physicochemical changes of b-LG apparently resulted from an alteration of forces stabilizing the structure of the protein.
对β-乳球蛋白（b-LG）的麦芽寡糖基和氨基葡萄糖基衍生物的物理化学性质进行了分析：比浓粘度、紫外差光谱、内源荧光、疏水性和圆二色性。这些衍生物的粘度随着与b-LG共价连接的碳水化合物质量的增加而增加。这些蛋白质的紫外差光谱和内源荧光显示，随着修饰程度的增加，b-LG芳香族氨基酸残基的微环境越来越多地暴露于蛋白质表面；并且这些残基的极性也随着修饰程度的增加而增加。随着修饰程度的增加，M-b-LG衍生物的疏水性降低，而G-b-LG衍生物的疏水性相对不变。这些蛋白质的圆二色性分析表明，b-LG广泛修饰衍生物的二级结构部分展开。因此，与b-LG共价连接的碳水化合物改变了许多物理化学性质。b-LG的这些物理化学变化显然是由稳定蛋白质结构的作用力的改变引起的。
