Disclosed is a physiologically active complex which comprises a
proteinaceous part with TNF activity and a high molecular part bound
artificially to the N-terminus of the proteinaceous part. The
proteinaceous part in the complex has the amino acid sequence of SEQ ID
NO:2 where Xaa is a member selected from the group consisting of
asparagine, alanine, arginine, serine, threonine, proline, methionine,
and leucine; while the high molecular part in the complex is a
homopolymer of polyethylene glycol, copolymer of polyethylene glycol, or
a derivative thereof.