We have combined dynamic light scattering measurements
with circular dichroism, and fluorescence spectroscopy to study
the effect of limited heat-induced aggregation of BSA on the structure
development in the complex forming water–gelatin–BSATA
system above the conformation transition temperature of gelatin.
We clearly established that the structure of the complexes formed
and the origin of the forces stabilizing interprotein complexes are
different in the case of the native, and the thermally aggregated
BSA.
In the contrast to native BSA, intermacromolecular interaction
of the BSATA with gelatin leads to formation of large complex particles
of the BSATA with gelatin, partial unfolding globular protein
and formation of the charged complex particles. These complex
particles are stabilized by both electrostatic and the secondary
forces (hydrophobic interaction and hydrogen bonds), whereas
complex particles in the gelatin–native BSA system stabilized by
only Coulomb forces [20].