TY - JOUR
T1 - Urea-Driven Epigallocatechin Gallate (EGCG) permeation into the Ferritin Cage, an innovative method for fabrication of Protein-Polyphenol Co-assemblies
AU - Yang, Rui
AU - Liu, Yuqian
AU - Meng, Demei
AU - Chen, Zhiyu
AU - Blanchard, Christopher L.
AU - Zhou, Zhongkai
N1 - Includes bibliographical references.
PY - 2017/2/22
Y1 - 2017/2/22
N2 - 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 0 (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) × 104 M-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.
AB - 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 0 (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) × 104 M-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.
KW - EGCG
KW - Ferritin
KW - Permeation
KW - Polyphenol protein interaction
KW - Urea
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U2 - 10.1021/acs.jafc.6b04671
DO - 10.1021/acs.jafc.6b04671
M3 - Article
C2 - 28158944
AN - SCOPUS:85013472583
VL - 65
SP - 1410
EP - 1419
JO - Journal of Agricultural and Food Chemistry
JF - Journal of Agricultural and Food Chemistry
SN - 0021-8561
IS - 7
ER -