Asialoglycoprotein - conjugated medicinal agent

A process for preparing a conjugated interferon of formula (1)

• P-(S)x-Gal-GA-INF (1)
• wherein
• P is a peptide residue of a human serum glycoprotein;
• S is a sugar residue of a human serum glycoprotein
• Gal is a galactose residue;
• GA is a glutaraldehyde residue;
• x is equal to or greater than 1;
• and
• INF is interferon, comprising:
• providing a Cohn fraction V supernatant of human serum;
• treating the Cohn fraction V supernatant of human serum to separate alpha(1)-acid glycoprotein having the formula P-(S)x-Gal-NANA therefrom, wherein NANA is N-acetyl neuraminic acid, and recovering the alpha(1)-acid glycoprotein;
• treating the recovered alpha(1)-acid glycoprotein with neuraminidase to remove sialic acid and to obtain asialoglycoprotein of formula P-(S)x-Gal;
• linking the asialoglycoprotein with interferon by means of a glutaraldehyde (GA) crosslinking method;
• and recovering the conjugated interferon of formula P-(S)x-Gal-GA-INF.

A process for preparing a conjugated interferon of formula (1)

• P-(S)x-Gal-GA-INF (1)
• wherein
• P is a peptide residue of a human serum glycoprotein;
• S is a sugar residue of a human serum glycoprotein
• Gal is a galactose residue;
• GA is a glutaraldehyde residue;
• x is equal to or greater than 1;
• and
• INF is interferon, comprising;
• providing human blood serum which includes a human serum glycoprotein of the formula P-(S)x-Gal-NANA, characterized in that the residue adjacent to the sugar residue is D-galactose (Gal) and the last residue is N-acetyl neuraminic acid (NANA);
• treating the human blood serum to separate the human serum glycoprotein P-(S)x-Gal-NANA from the human blood serum and recovering the human serum glycoprotein P-(S)x-Gal-NANA;
• treating the recovered human serum glycoprotein (P-(S)x-Gal-NANA with neuraminidase to remove NANA and to obtain asialoglycoprotein (P-(S)x-Gal);
• linking the asialoglycoprotein, (P-(S)x-Gal), with interferon by means of a glutaraldehyde(GA) crosslinking method;
• and
• recovering the conjugated interferon of formula P-(S)x-Gal-GA-INF (1).