Urea-Driven Epigallocatechin Gallate (EGCG) Permeation into the Ferritin Cage, an Innovative Method for Fabrication of Protein-Polyphenol Co-assemblies.
The 8 nm diameter cavity endows the ferritin cage with a natural space to encapsulate food components. In this work, urea was explored as a novel medium to facilitate the formation of ferritin-polyphenol co-assemblies. Results indicated that urea (20 mM) could expand the 4-fold channel size of apo-red bean ferritin (apoRBF) with an increased initial iron release rate υ0(0.22 ± 0.02 μM min-1) and decreased α-helix content (5.6%). Moreover, urea (20 mM) could facilitate the permeation of EGCG into the apoRBF without destroying the ferritin structure and thus form ferritin-EGCG co-assemblies (FECs) with an encapsulation ratio and loading capacity of 17.6 and 2.1% (w/w), respectively. TEM exhibited that FECs maintained a spherical morphology with a 12 nm diameter in size. Fluorescence analysis showed that urea intervention could improve the binding constant K [(1.22 ± 0.8) × 104M-1] of EGCG to apoRBF. Furthermore, the EGCG thermal stability was significantly improved (20-60 °C) compared with free EGCG. Additionally, this urea-involved method was applicable for chlorogenic acid and anthocyanin encapsulation by the apoRBF cage. Thus, urea shows potential as a novel potential medium to encapsulate and stabilize bioactive polyphenols for food usage based on the ferritin protein cage structure.
Key Laboratory of Food Nutrition and Safety, Ministry of Education, School of Food Engineering and Biotechnology, Tianjin University of Science and Technology , Tianjin 300457, China.|Tianjin Food Safety & Low Carbon Manufacturing Collaborative Innovation Center , Tianjin 300457, China.
Rui
http://orcid.org/0000-0002-7281-7672
R
Yang
Key Laboratory of Food Nutrition and Safety, Ministry of Education, School of Food Engineering and Biotechnology, Tianjin University of Science and Technology , Tianjin 300457, China.
Yuqian
Y
Liu
Key Laboratory of Food Nutrition and Safety, Ministry of Education, School of Food Engineering and Biotechnology, Tianjin University of Science and Technology , Tianjin 300457, China.
Demei
D
Meng
Key Laboratory of Food Nutrition and Safety, Ministry of Education, School of Food Engineering and Biotechnology, Tianjin University of Science and Technology , Tianjin 300457, China.
Zhiyu
Z
Chen
ARC Industrial Transformation Training Centre for Functional Grains , Wagga Wagga, NSW 2678, Australia.
Christopher L
CL
Blanchard
Key Laboratory of Food Nutrition and Safety, Ministry of Education, School of Food Engineering and Biotechnology, Tianjin University of Science and Technology , Tianjin 300457, China.|Tianjin Food Safety & Low Carbon Manufacturing Collaborative Innovation Center , Tianjin 300457, China.
Zhongkai
Z
Zhou
D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D002726:Chlorogenic Acid / Q000737:chemistry; D005293:Ferritins / Q000737:chemistry*; D007700:Kinetics; D059808:Polyphenols / Q000737:chemistry*; D014508:Urea / Q000737:chemistry*
D059808:Polyphenols; D002726:Chlorogenic Acid; D002392:Catechin; D014508:Urea; D005293:Ferritins; C045651:epigallocatechin gallate
EGCG; ferritin; permeation; polyphenol−protein interaction; urea