| Full text | |
| Author(s): |
Sun, Yang
[1, 2, 3]
;
Zhang, Juntao
[4]
;
Wang, Haibo
[4]
;
Wang, Tingting
[1]
;
Cheng, Hua
[1]
;
Yu, Bo
[1]
;
Oliveira, Cristiano L. P.
[3]
Total Authors: 7
|
| Affiliation: | [1] Hubei Univ Arts & Sci, Sch Chem Engn, Xiangyang 441053, Hubei - Peoples R China
[2] Tsinghua Univ, Sch Life Sci, Beijing 100084 - Peoples R China
[3] Univ Sao Paulo, Inst Fis, Rua Matao 1371, BR-05314970 Sao Paulo - Brazil
[4] Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Hubei - Peoples R China
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | FOOD HYDROCOLLOIDS; v. 82, p. 19-28, SEP 2018. |
| Web of Science Citations: | 2 |
| Abstract | |
With well-known nutritional properties, casein contributes to about 80% of protein content in milk and has been classified as highly intrinsically disordered protein (IDP). In this paper, the sulfate dodecyl sodium (SDS)-induced conformational changes of bovine casein were studied by multi-techniques. Isothermal titration calorimetry (ITC) and differential scanning calorimetry (DSC) were used to obtain the stoichiometry of conformational changes and the thermal stability of the formed complexes. Spectral results indicated that casein presented a higher helical content but loss of tertiary structure above critical micelle concentration of SDS, namely, the so-called molten globule like state. The thermal selfassociation of casein could be prevented by SDS according to far-UV CD even at 70 degrees C. The H-1 NMR spectrum of casein showed that the resonance around 1.0 ppm, the region of a-hydrogen, shifted to the higher field, and the aromatic region around 5.5-8.0 ppm shifted to the lower field, while the NOESY spectra of casein exhibited few chemical shifts with binding of SDS. Combining the results of dynamic light scattering (DLS), scanning electron microscope (SEM) and small angle x-ray scattering (SAXS), one obtains that casein micelles presented an elliptical shape of similar to 800 nm in diameter and upon binding with SDS, the casein micelles disassociated into more compact globular particles of 10 nm in diameter with a core-shell structure composed by SDS molecules and casein proteins. The present work, not only provides molecular insights into the mechanism of SDS-induced stability of a model IDP, casein, but also helps understand the role of surfactants on the structureefunction relationship of bovine casein in the food industry. (C) 2018 Elsevier Ltd. All rights reserved. (AU) | |
| FAPESP's process: | 13/09604-6 - Structural and Thermodynamic studies of proteins, surfactants and protein complexes |
| Grantee: | Sun Yang |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 15/01732-0 - Development of analysis and modeling methods for diffraction and small-angle scattering |
| Grantee: | Cristiano Luis Pinto de Oliveira |
| Support Opportunities: | Regular Research Grants |