title: Mechanism of Formation and Stabilization of Nanoparticles Produced by Heating Electrostatic Complexes of WPI-Dextran Conjugate and Chondroitin Sulfate.
abstract: Protein conformational changes were demonstrated in biopolymer nanoparticles, and molecular forces were studied to elucidate the formation and stabilization mechanism of biopolymer nanoparticles. The biopolymer nanoparticles were prepared by heating electrostatic complexes of whey protein isolate (WPI)-dextran conjugate (WD) and chondroitin sulfate (ChS) above the denaturation temperature and near the isoelectric point of WPI. The internal characteristics of biopolymer nanoparticles were analyzed by several spectroscopic techniques. Results showed that grafted dextran significantly (p < 0.05) prevented the formation of large aggregates of WD dispersion during heat treatment. However, heat treatment slightly induced the hydrophobicity changes of the microenvironment around fluorophores of WD. ChS electrostatic interaction with WD changed the fluorescence intensity of WD regardless of heat treatment. Far-UV circular dichroism (CD) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopies confirmed that glycosylation and ionic polysaccharide did not significantly cause protein conformational changes in WD and ChS (WDC) during heat treatment. In addition, hydrophobic bonds were the major molecular force for the formation and stabilization of biopolymer nanoparticles. However, hydrogen bonds slightly influenced their formation and stabilization. Ionic bonds only promoted the formation of biopolymer nanoparticles, while disulfide bonds partly contributed to their stability. This work will be beneficial to understand protein conformational changes and molecular forces in biopolymer nanoparticles, and to prepare the stable biopolymer nanoparticles from heating electrostatic complexes of native or glycosylated protein and polysaccharide.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University , Lihu Road 1800, Wuxi, Jiangsu 214122, People's Republic of China.|College of Biological and Chemical Engineering, Anhui Polytechnic University , Beijing Middle Road, Wuhu, Anhui 241000, People's Republic of China.
authors.forename: Qingyuan
authors.initials: Q
authors.lastname: Dai
authors.affiliation: College of Biological and Chemical Engineering, Anhui Polytechnic University , Beijing Middle Road, Wuhu, Anhui 241000, People's Republic of China.
authors.forename: Xiuling
authors.initials: X
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University , Lihu Road 1800, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Jingyang
authors.initials: J
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University , Lihu Road 1800, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Eric
authors.initials: E
authors.lastname: Karangwa
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University , Lihu Road 1800, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Shuqin
authors.initials: S
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University , Lihu Road 1800, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University , Lihu Road 1800, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Chengsheng
authors.initials: C
authors.lastname: Jia
mesh_terms: D002809:Chondroitin Sulfates / Q000737:chemistry*; D003911:Dextrans / Q000737:chemistry*; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D055672:Static Electricity; D000067816:Whey Proteins / Q000737:chemistry*
chemical_list: D003911:Dextrans; D011108:Polymers; D000067816:Whey Proteins; D002809:Chondroitin Sulfates
keywords: chondroitin sulfate; conjugate; dextran; electrostatic complex; nanoparticle; stabilization; whey protein isolate