Interferon-albumin conjugate with conserved biological activity.

The heterobifunctional reagent N-succinilimidyl 3-(2-pyridylthio)propionate (SPDP) was used for the preparation of a disulphide-linked conjugate between Namalwa lymphoblastoid interferon and serum albumin. The linkage of interferon to albumin did not reduce the ability to protect MDBK cells against infection by vesicular stomatitis virus (VSV). The conjugate did not dissociate into free interferon and albumin under conditions prevailing in the assay for interferon activity. The rate of clearance of the interferon-albumin conjugate from the mouse circulatory system was somewhat slower than that of free interferon.