Open AccessPeroxidase Activity of a c ‐Type Cytochrome b 5 in the Non‐Native State is Comparable to that of Native Peroxidases
Author(s) -
Hu Shan,
He Bo,
Du KeJie,
Wang XiaoJuan,
Gao ShuQin,
Lin YingWu
Publication year - 2017
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201700055
Subject(s) - peroxidase , heme , guanidine , chemistry , native state , cytochrome c peroxidase , horseradish peroxidase , cytochrome c , hemeprotein , protein design , protein engineering , stereochemistry , enzyme , substrate (aquarium) , combinatorial chemistry , biochemistry , protein structure , biology , ecology , mitochondrion
The design of artificial metalloenzymes has achieved tremendous progress, although few designs can achieve catalytic performances comparable to that of native enzymes. Moreover, the structure and function of artificial metalloenzymes in non‐native states has rarely been explored. Herein, we found that a c ‐type cytochrome b 5 (Cyt b 5 ), N57C/S71C Cyt b 5 , with heme covalently attached to the protein matrix through two Cys–heme linkages, adopts a non‐native state with an open heme site after guanidine hydrochloride (Gdn ⋅ HCl)‐induced unfolding, which facilitates H 2 O 2 activation and substrate binding. Stopped‐flow kinetic studies further revealed that c ‐type Cyt b 5 in the non‐native state exhibited impressive peroxidase activity comparable to that of native peroxidases, such as the most efficient horseradish peroxidase. This study presents an alternative approach to the design of functional artificial metalloenzymes by exploring enzymatic functions in non‐native states.