Aggregation behavior of giant amphiphiles prepared by cofactor reconstitution

We report on biohybrid surfactants, termed "giant amphiphiles", in which a protein or an enzyme acts as the polar head group and a synthetic polymer as the apolar tail. It is demonstrated that the modification of horse-radish peroxidase (HRP) and myoglobin (Mb) with an apolar polymer chain through the cofactor reconstitution method yields giant amphiphiles that form sherical aggregates (vesicles) in aqueous solution. Both HRP and Mb retain their original functionality when modified iwth a single polystyrene chain, but reconstitution has an effect on their activities. In the case of HRP the enzymatic activity decreases and for Mb the stability of the dioxygen myoglobin (oxy-Mb) complex is reduced, which is probably the result of a distrubed binding of the heme in the apo-protein or a reduced access of the substrate to the active site of the enzyme or protein.