Site-directed enzymatic PEGylation of the human granulocyte colony-stimulating factor

摘要: Poly(ethylene glycol) (PEG) is a widely used polymer employed to increase the circulating half-life of proteins in blood and decrease their immunogenicity antigenicity. PEG attaches free amines, typically at lysine residues or N-terminal amino acid. This lack selectivity can present problems when PEGylated protein therapeutic being developed, because predictability activity manufacturing reproducibility are needed for regulatory approval. Enzymatic modification one route overcome this limitation. Bacterial transglutaminases enzyme candidates site-specific modification, but they also have rather broad specificity. The need arises be able predict a priori potential PEGylation sites on interest and, especially, design mutants where unique introduced needed. We investigated feasibility computational approach problem, using human granulocyte colony-stimulating factor as test case. selected therapeutically relevant represents challenging it contains 17 sites. Our results show that combination methods allows identification specific glutamines substrates enzymatic by microbial transglutaminase, possible rationally modify introduce moieties desired sites, thus allowing selection regions unlikely interfere with biological protein.