Biliverdin-copper complex at physiological pH
Authorized Users Only
AuthorsDimitrijević, Milena S.
Bogdanović Pristov, Jelena
Article (Published version)
MetadataShow full item record
Biliverdin (BV), a product of heme catabolism, is known to interact with transition metals, but the details of such interactions under physiological conditions are scarce. Herein, we examined coordinate/redox interactions of BV with Cu2+ in phosphate buffer at pH 7.4, using spectrophotometry, HESI-MS, Raman spectroscopy, 1 H NMR, EPR, fluorimetry, and electrochemical methods. BV formed a stable coordination complex with copper in 1 : 1 stoichiometry. The structure of BV was more planar and energetically stable in the complex. The complex showed strong paramagnetic effects that were attributed to an unpaired delocalized e−. The delocalized electron may come from BV or Cu2+, so the complex is formally composed either of BV radical cation and Cu1+ or of BV radical anion and Cu3+. The complex underwent oxidation only in the presence of both O2 and an excess of Cu2+, or a strong oxidizing agent, and it was resistant to reducing agents. The biological effects of the stable BV metallocomplex ...containing a delocalized unpaired electron should be further examined, and may provide an answer to the long-standing question of high energy investment in the catabolism of BV, which represents a relatively harmless molecule per se.
Source:Dalton Transactions, 2019, 48, 18, 6061-6070
- Modulation of antioxidative metabolism in plants for improvement of plant abiotic stress tolerance and identification of new biomarkers for application in remediation and monitoring of degraded biotopes (RS-43010)
- Strengthening of the MagBioVin Research and Innovation Team for Development of Novel Approaches for Tumour Therapy based on Nanostructured Materials (EU-621375)
- Peer-reviewed version: http://cer.ihtm.bg.ac.rs/handle/123456789/2933