%0 Journal Article
%T Interaction-induced structural transformation of lysozyme and kappa-carrageenan in binary complexes.
%A Makshakova ON
%A Bogdanova LR
%A Faizullin DA
%A Ermakova EA
%A Zuev YF
%A Sedov IA
%J Carbohydr Polym
%V 252
%N 0
%D Jan 2021 15
%M 33183628
%F 10.723
%R 10.1016/j.carbpol.2020.117181
%X 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.