Preservation of myocardial energy status by bovine hemoglobin solutions during ischemia

Designed Fabrication of Polymer-Mediated MOF-Derived Magnetic Hollow Carbon Nanocages for Specific Isolation of Bovine Hemoglobin

It is highly required to develop well-designed separation materials for the specific isolation of certain proteins in proteomic research. Herein, the new type of metal-organic framework (MOF)-derived polymer-mediated magnetic hollow nanocages was fabricated via stress-induced orientation contraction, which was further applied for specific enrichment of proteins. The core-shell nanocomposites comprised of polymer-mediated ZIF-67 cores and polydopamine (PDA) shells, after annealing, generated magnetic hollow carbon nanocages with hierarchical pores and structures. Particularly, the magnetic carbonized PDA@F127/ZIF-67 hollow nanocages exhibited a remarkable adsorption capacity toward bovine hemoglobin (BHB) up to 834.3 mg g^-1, which was significantly greater than that of the directed carbonized ZIF-67 nanoparticles. The results also exhibited the notable specificity of the obtained nanocages on complex biosamples, including intact mixed proteins and fetal calf serum. The hierarchically hollow porous structure greatly improves the specific surface area and reduces the mass transfer resistance, leading to enhanced high adsorption for target protein BHB. This novel method will be promising for the applications in purification and enrichment of biomacromolecules for complex biosamples, which successfully solve the problem of low adsorption efficiency and tedious separating process of the previous MOF-derived materials.

Molecular insight into the binding aspects of benzo[c]phenanthridine alkaloid nitidine with bovine hemoglobin: A biophysical exploration

The association of a putative bioactive alkaloid nitidine (NIT) with blood protein bovine hemoglobin (BHb) was investigated by employing various biophysical and molecular docking techniques. NIT binding to BHb was first characterized by hypochromic effect on the Soret band absorption of BHb from spectrophotometric studies. Spectrofluorimetric titration and unchanged fluorescence lifetime of BHb confirmed ground state complexation followed by the static nature of the emission quenching mechanism of the protein induced by NIT. Substantial conformational changes in the protein structure were established from circular dichroism study. Conformational perturbation results a lowering in the α-helical organization of the tetrameric protein structure. Thermodynamics of the binding suggest that the binding is exothermic with a favourable small positive entropy change and negative enthalpy change making a sense of electrostatic interaction as the major acting force. Experimentally calculated free energy change for the NIT-BHb interaction was found to be -7.50 kcal mol^-1 which is in well agreement to the theoretical docking energy value of -6.36 kcal mol^-1. AutoDock based molecular docking suggests the internal cavity of BHb as the preferred binding position of NIT. Overall this manuscript depicts consequences on the molecular interaction of NIT with BHb from structural and energetic standpoints providing a profound insight into protein-ligand association.