TY - JOUR
T1 - Galloylated catechins as potent inhibitors of angiotensin converting enzyme
AU - Liu, Zhe
AU - Nakamura, Toshiyuki
AU - Munemasa, Shintaro
AU - Murata, Yoshiyuki
AU - Nakamura, Yoshimasa
N1 - Publisher Copyright:
© 2016, Japanese Society for Food Science and Technology.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016
Y1 - 2016
N2 - In the present study, we investigated the inhibitory effects of four tea catechins, including (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg), on angiotensin converting enzyme (ACE) activity in vitro. Each catechin treatment significantly reduced the ACE activity with the order of potency being EGCg > ECg > EGC = EC. The addition of 1 mM borate significantly recovered the reduced ACE activities by tea catechins, suggesting that hydroxyl groups at the B-ring or at a galloyl moiety play an important role in the ACE-inhibitory mechanism. The covalent modification of ACE by tea catechins was also observed by a redox-cycling staining experiment. A Lineweaver-Burk plot indicated that EGC and ECg were noncompetitive inhibitors. The galloylated catechins might more potently inhibit ACE activity in an allosteric manner through the interaction of the galloyl moiety with the non-catalytic site of ACE.
AB - In the present study, we investigated the inhibitory effects of four tea catechins, including (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg), on angiotensin converting enzyme (ACE) activity in vitro. Each catechin treatment significantly reduced the ACE activity with the order of potency being EGCg > ECg > EGC = EC. The addition of 1 mM borate significantly recovered the reduced ACE activities by tea catechins, suggesting that hydroxyl groups at the B-ring or at a galloyl moiety play an important role in the ACE-inhibitory mechanism. The covalent modification of ACE by tea catechins was also observed by a redox-cycling staining experiment. A Lineweaver-Burk plot indicated that EGC and ECg were noncompetitive inhibitors. The galloylated catechins might more potently inhibit ACE activity in an allosteric manner through the interaction of the galloyl moiety with the non-catalytic site of ACE.
KW - Angiotensin converting enzyme
KW - Covalent modification
KW - Non-competitive inhibition
KW - Tea catechins
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U2 - 10.3136/fstr.22.847
DO - 10.3136/fstr.22.847
M3 - Article
AN - SCOPUS:85007493456
VL - 22
SP - 847
EP - 851
JO - Food Science and Technology Research
JF - Food Science and Technology Research
SN - 1344-6606
IS - 6
ER -