The identification of PEGylation sites is essential in the characterization of PEGylated therapeutic proteins. This report describes a simple and novel method of finding poly(ethylene glycol) (PEG) conjugation sites in PEGylated proteins by using a hetero-functional biotin-PEG-N-hydroxyl succinimide derivative. PEGylated lysozyme species having a biotin moiety at each PEG chain end were separat...

To prepare PEGylated recombinant human granulocyte colony-stimulating factor (rHuG-CSF) with enhanced pharmacokinetic properties, we prepared a cysteine-substituted mutant of rHuG-CSF (mrHuG-CSF). For site-specific PEGylation of mrHuG-CSF, Threonine 134 residue that is one of the glycosylation sites and thought not to be critical in structure and function of rHuG-CSF was substituted by Cysteine...

Poly(ethylene glycol) (PEG) is a highly investigated polymer for the covalent modification of biological macromolecules and surfaces for many pharmaceutical and biotechnical applications. In the modification of biological macromolecules, peptides and proteins are of extreme importance. Reasons for PEGylation (i.e. the covalent attachment of PEG) of peptides and proteins are numerous and include...

The purpose of this study is to apply optical waveguide (OWG) spectroscopy to characterize the encapsulation behavior of enzymes modified with polyethylene glycol (PEG), i.e. pegylation, in a hydrophobic mesoporous silica film. For that purpose, pegylated myoglobin (PEG-Mb) was introduced into the silica mesopores modified with octadecylsilyl (ODS) groups and studied by OWG spectroscopy. OWG ...

Conjugation with polyethylene glycol (PEG), known as PEGylation, has been widely used to improve the bioavailability of proteins and low molecular weight drugs. The covalent conjugation of PEG to the carbohydrate moiety of a protein has been mainly used to enhance the pharmacokinetic properties of the attached protein while yielding a more defined product. Thus, glycoPEGylation was successfully...

The covalent attachment of polyethylene glycol (PEG) to therapeutic proteins can improve their physicochemical properties. In this work we utilized the non-natural amino acid p-azidophenylalanine (pAzF) in combination with the chemoselective Staudinger-phosphite reaction to install branched PEG chains to recombinant unglycosylated erythropoietin (EPO) at each single naturally occurring glycosyl...

conjugation of methotrexate (mtx) (mw 454) with different molecular weights of polyethylene glycol (peg) including methoxy-peg (mpeg) 750 d and 5000 d and diol-peg 35000 d led to compounds that are physicochemically highly different from the parent compound, mtx. in this study, an hplc system consisting of c8 column and uv detector (?=342 nm), using a mixture of 30:70 v/v phosphate-citrate buff...