title: Conformational Transition of Polyelectrolyte As Influenced by Electrostatic Complexation with Protein.
abstract: Conformation and conformational transitions are essential for the biological and technological functions of natural polyelectrolytes, for example, DNA. This study aims to clarify how the conformational transition of natural polyelectrolyte is affected and tuned by electrostatic complexation with protein as encountered in many biological processes. A model protein/polyelectrolyte system, β-lactoglobulin (β-lg) and κ-carrageenan (κ-car), was used for the investigation. The effect was found to be determined by the molecular state of β-lg/κ-car electrostatic complexation and the molecular weight of protein. β-lg/κ-car complexation in soluble state had a subtle effect on the coil-to-helix transition of κ-car, while that in insoluble state greatly suppressed it. On the basis of the McGhee-Hippel theory, a quantitative model was successfully developed to describe the effect of protein/polyelectrolyte electrostatic complexation on the conformational transition of polyelectrolyte. The model can also provide additional information on the change of tertiary structure of β-lg upon electrostatic complexation with κ-car. Moreover, it was found that β-lg or its hydrolysates with a molecular weight larger than 2000 Da hindered the conformational transition of κ-car, while those with a molecular weight lower than 1000 Da promoted it. The observations offer a promising approach to control the conformational transition and related properties of polyelectrolytes for technological applications.
authors: Glyn O. Phillips Hydrocolloid Research Centre, School of Food and Biological Engineering and ‡Hubei Collaborative Innovation Centre for Industrial Fermentation, Hubei University of Technology , Wuhan 430068, China.
authors: Yiping
authors: Y
authors: Cao
authors: Glyn O. Phillips Hydrocolloid Research Centre, School of Food and Biological Engineering and ‡Hubei Collaborative Innovation Centre for Industrial Fermentation, Hubei University of Technology , Wuhan 430068, China.
authors: Shugang
authors: S
authors: Li
authors: Glyn O. Phillips Hydrocolloid Research Centre, School of Food and Biological Engineering and ‡Hubei Collaborative Innovation Centre for Industrial Fermentation, Hubei University of Technology , Wuhan 430068, China.
authors: Yapeng
authors: Y
authors: Fang
authors: Glyn O. Phillips Hydrocolloid Research Centre, School of Food and Biological Engineering and ‡Hubei Collaborative Innovation Centre for Industrial Fermentation, Hubei University of Technology , Wuhan 430068, China.
authors: Katsuyoshi
authors: K
authors: Nishinari
authors: Glyn O. Phillips Hydrocolloid Research Centre, School of Food and Biological Engineering and ‡Hubei Collaborative Innovation Centre for Industrial Fermentation, Hubei University of Technology , Wuhan 430068, China.
authors: Glyn O
authors: GO
authors: Phillips
mesh_terms: D002351:Carrageenan / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007782:Lactoglobulins / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D008970:Molecular Weight; D000071228:Polyelectrolytes / Q000737:chemistry*; D055672:Static Electricity; D013696:Temperature
chemical_list: D007782:Lactoglobulins; D000071228:Polyelectrolytes; D002351:Carrageenan