CYSTEINE ADDED VARIANTS OF POLYPEPTIDES AND CHEMICAL MODIFICATIONS THEREOF

摘要

Cysteine added variants ("CAVs") of EPO are provided having one or more cysteine residues substituted for selected naturally occurring amino acid residues, or inserted into the polypeptide sequence, and preferably being further modified by deletion of certain N-terminal amino acids. Such CAVs may be additionally modified by the coupling of sulfhydryl reactive compounds to the introduced cysteine residue(s) without loss of bioactivity to produce selected homogeneously modified EPO and improved pharmaceutical compositions containing the same.