Interaction behaviors between chitosan and hemoglobin

The interaction and association between chitosan and hemoglobin (Hb) are studied by UV–vis and fluorescence spectroscopies, viscometry, circular dichroism, dynamic and static light scattering. Chitosan can obviously associate with Hb to form protein–chitosan complexes, which affects microstructure of Hb. The distance between the first association site of chitosan with 214-tryptophan residue in Hb is about 5.473 nm. The intrinsic UV–vis absorption and fluorescence intensities of Hb increase with an increase of chitosan concentration. The α-helix in Hb is drawn and changed into β-sheet.