Method of Covalently Modifying Proteins with Organic Molecules to Prevent Aggregation

A system and method for preventing protein aggregation is developed by covalent modification of proteins with organic molecules that can preserve the native protein folding. Proteins are covalently modified with sugar alcohols or cyclodextrins (organic Kosmotropes) or other small molecule drugs by water-driven bioorganic reactions in water. In the water-driven bioorganic reactions, the reagent is stable in water and can modify lysine residues or cysteine residue of a protein at physiological conditions with high yield and fast rate. Proteins and antibodies will be modified by non-natural sugar alcohols. As a result, the efficacy of protein drugs (reduction in aggregation and enzymatic degradation, and increase in blood stream life time) may be improved.