The interactions between κ-carrageenan and hen egg-white lysozyme have been studied. In dilute solutions, the insoluble complexes with constant κ-carrageenan/lysozyme ratio of 0.3, or 12 disaccharide units per mole of protein are formed. FTIR-spectroscopy revealed that κ-carrageenan retains its unordered conformation and induces the rise of β-structure in lysozyme. In the complexes formed in concentrated mixtures, κ-carrageenan adopts helical conformation and lysozyme retains its native-like structure. These complexes contain 21 disaccharide units per mole of protein. Molecular modeling showed that flexible coil and rigid double helix of κ-carrageenan have different binding patterns to lysozyme surface. The latter has a strong preference to positively charged spots in lysozyme α-domain while the former also interacts to protein β-domain and stabilizes short-living β-structures. The obtained results confirm the preference of unordered κ-carrageenan to β-structure rich protein regions, which can be further used in the development of carrageenan-based protection of amyloid-like aggregation of proteins.

已经研究了κ-角叉菜胶与鸡蛋清溶菌酶之间的相互作用。在稀溶液中，形成的不溶性复合物具有恒定的κ-角叉菜胶/溶菌酶比率为0.3，或每摩尔蛋白质12个二糖单元。FTIR光谱显示，κ-角叉菜胶保留其无序构象并诱导溶菌酶中β结构的上升。在浓缩混合物中形成的复合物中，κ-角叉菜胶呈螺旋构象，溶菌酶保留其天然结构。这些复合物每摩尔蛋白质包含21个二糖单元。分子建模表明，κ-角叉菜胶的柔性螺旋和刚性双螺旋与溶菌酶表面的结合方式不同。后者对溶菌酶α-结构域中带正电的斑点具有强烈的偏好，而前者也与蛋白质β-结构域相互作用并稳定短命的β-结构。获得的结果证实了无序κ-角叉菜胶对富含β-结构的蛋白质区域的偏好，其可以进一步用于基于角叉菜胶的蛋白质的淀粉样样聚集的保护的发展。