ABSTRACT
This chapter focuses on work of proteins conjugated with synthetic macromolecule, polyethylene glycol (PEG), and their potential medical and biotechnological processes. Proteins can be modified chemically by attaching synthetic and natural macromolecules to the surface of the protein molecule. This manipulation of protein modification with polymers can eliminate some drawbacks of native proteins and improve their properties. Modification of asparaginase with the higher molecular weight form of monomethoxy polyethylene glycol resulted in a greater reduction of the immunoreactivity with antiasparaginase antibodies and retention of the enzymic activity. Upon modification of arginase with PEG in which 53% of amino groups were coupled, PEG-arginase was rendered to be both nonimmunogenic and nonantigenic and altered its kinetic properties. An application of PEG-enzyme conjugates is biotechnological processes. The conjugates become soluble and active in organic solvents so that various kinds of organic substances can be synthesized by PEG enzymes.
