A recombinant mutein of human alpha interferon with at least one glycosylation site at one position of its amino acid sequence which forms part of an alpha-helix-type secondary structure, a gene coding for said mutein, a method for producing said gene, a method for obtaining a eukaryotic cell that produces said mutein, a method for producing said mutein, a method for purifying said mutein, a pharmaceutical composition of said mutein, and the use of said mutein for preparing a medicinal product.