Refolding of Hemoglobin Under Macromolecular Confinement: Impersonating In Vivo Volume Exclusion

Spectroscopic characterization of triazine based covalent organic framework tempted changes in the structure of hemoglobin

The present study aims to understand changes in the Hemoglobin (Hb) structure in the presence of a triazine based covalent organic framework (COF) through spectroscopic characterization. Covalent Organic Frameworks (COFs) due to their unique properties have been utilized in diverse fields including bio-applications. Utilization of COFs for conjugate formation with proteins will lead to the integration of biology and framework materials that can help in the development of bioconjugates for advanced bio-based applications such as diagnostics, therapeutics, and bioengineering. However, vital is to have a fundamental understanding of protein conformation in protein-COF conjugate. Herein, a triazine based COF has been synthesized via solvothermal method, termed TATF-COF which has been utilized for the formation of a conjugate with hemoglobin (Hb). Thereafter, studies have been performed to understand Hb structure in the presence of TATF-COF. Results from UV-vis, Fluorescence, and UV-CD spectroscopy studies revealed that in the presence of TATF-COF, there was a slight alteration in the Hb structure due to binding interactions between them and conjugate formation. Moreover, micrographs obtained from electron microscopy displayed formation of conjugate between Hb and TATF-COF result of binding interactions. DLS and zeta potential results also revealed conjugate formation due to binding interactions between TATF-COF and Hb. Thermal stability of Hb was also maintained as TATF-COF had insignificant effect on the Tm value of Hb. Overall, there was a slight alternation in the Hb native conformation due to binding interactions, however, TATF-COF was compatible with Hb as the protein's native structure was well-preserved.