Dissociation of aggregated ferroheme complexes and protoporphyrin IX by water-soluble polymers

The ferroheme-pyridine complex, ferroheme and protoporphyrin IX form the aggregates by the hydrophobic interaction in aqueous solutions. We found by spectrophotometric and fluorometric measurements that the aggregates dissociated into the monomers by the addition of water-soluble polymers, such as, poly(ethyleneoxide), poly(vinylalcohol), poly(vinylpyrrolidone) and poly(styrene sulfonate). The dissociation by the polymers proceeded as their hydrophobicities increased. The aggregated ferroheme was effectively dissociated by the copolymers of 4-vinylpyridine which were water-soluble polymer-ligands.