Its high molecular weight endows benzo[a]pyrene (BaP) with strong adsorption to soil, causing serious soil contamination. Our previous study has reported that hemoglobin (Hb) is able to oxidize organic pollutants in the presence of H2O2. This present study showed that Hb catalytic mechanism for BaP oxidation was similar to that of lignin peroxidase. 2-Methyl-3-vinylmaleimide was confirmed as a major degradation intermediate of BaP by Hb catalysis. In addition, BaP was shown to be degraded by heme (Hm)-catalyzed reaction, suggesting that Hm of Hb is the essential catalytic center. Rate constants (k) for BaP oxidation by Hm-catalyzed reaction were 0.4954 h−1. The major degradation intermediate by Hm-catalyzed reaction is 3,3′,5,5′-tetramethylbiphenyl. While values of Km and Vmax of Hb and Hm are very similar, kcat values was 100 times higher with Hb than with Hm. But kcat value for Hb was much lower than that for lignin peroxidase H2. All the results above suggested that Hb-catalyzed reactions efficiently degrade BaP in aqueous condition. Thus, we suggest that Hb for oxygen carrier in blood could be employed as a biocatalyst (i.e., hemoglobin peroxidase) for BaP degradation in the environment, due to the high availability of Hb.
Bibliographical noteFunding Information:
This research was supported in part by the Hankuk University of Foreign Studies (2018). This research was also supported in part by the Institute of Life Science and Natural Resources, Korea University, Seoul, Korea (2018). This research was also supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2018R1D1A1B07049190).
© 2020 Elsevier Ltd
- Biocatalytic reaction
ASJC Scopus subject areas
- Environmental Engineering
- General Chemistry
- Environmental Chemistry
- Public Health, Environmental and Occupational Health
- Health, Toxicology and Mutagenesis