• myoglobin
• n-DSC
• polyphosphoesyers
• protein-polymer conjugates

Protein-polymer conjugates are used to treat several diseases, therefore the design of novel efficient conjugates is very promising for academia and industry. Here, we present the synthesis and characterization of novel PEEP-myoglobin conjugates. PEEP (poly(ethyl ethylene phosphate)) belongs to polyphosphoesters, a class of biocompatible and biodegradable polymers, promising candidate to substitute the “gold standard” poly(ethylene glycol) (PEG) in biomedical field, which can cause long term effects as it is not degradable. PEEP-ylated conjugates with variable polymer chains were synthesized and compared with PEGylated myoglobin, in order to understand how structure, number, length of the polymer influence protein’s features and properties. Measures of activity, absorbance, calorimetry and fluorimetry on the conjugates show a decrease in unfolding temperature and activity, but in all the cases the loss does not affect irremediably the protein’s features under physiological conditions. Furthermore PEG shows to stabilize myoglobin preventing aggregation and increasing the unfolding reversibility. We detected a decreasing trend in observed properties linked to the increase number of chains and polymer length.