排序方式: 共有27条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Dr. Ambika Bhagi-Damodaran Maximilian Kahle Yelu Shi Prof. Dr. Yong Zhang Prof. Dr. Pia Ädelroth Prof. Dr. Yi Lu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(23):6722-6726
Heme-copper oxidase (HCO) is a class of respiratory enzymes that use a heme-copper center to catalyze O2 reduction to H2O. While heme reduction potential (E°′) of different HCO types has been found to vary >500 mV, its impact on HCO activity remains poorly understood. Here, we use a set of myoglobin-based functional HCO models to investigate the mechanism by which heme E°′ modulates oxidase activity. Rapid stopped-flow kinetic measurements show that increasing heme E°′ by ca. 210 mV results in increases in electron transfer (ET) rates by 30-fold, rate of O2 binding by 12-fold, O2 dissociation by 35-fold, while decreasing O2 affinity by 3-fold. Theoretical calculations reveal that E°′ modulation has significant implications on electronic charge of both heme iron and O2, resulting in increased O2 dissociation and reduced O2 affinity at high E°′ values. Overall, this work suggests that fine-tuning E°′ in HCOs and other heme enzymes can modulate their substrate affinity, ET rate and enzymatic activity. 相似文献
6.
7.
8.
9.
10.