Abstract: The present invention refers to a secretion-competent mutein of the ?-subunit of human Interleukin 27 and to a human heterodimeric Interleukin 27. The present invention further refers to a nucleic acid molecule comprising a nucleotide sequence encoding a secretion-competent mutein of the ?-subunit of human Interleukin 27 or the human heterodimeric Interleukin 27, to a host cell containing a nucleic acid molecule comprising a nucleotide sequence encoding a secretion-competent mutein of the ?-subunit of human Interleukin 27 or of the human heterodimeric Interleukin 27. The invention also refers to an immune modulator comprising a secretion-competent mutein of the ?-subunit of human Interleukin 27 or of the human heterodimeric Interleukin 27, to the respective use thereof as well as to a method of producing said secretion-competent muteins and to a secretion-incompetent mutein of the ?-subunit of mouse Interleukin 27 and a secretion-competent mutein of the ?-subunit of mouse Interleukin 27.

Abstract: The present invention relates to a method of producing a modified protein having an increased stability and/or improved folding efficiency as compared to the unmodified protein, the method comprising (i) modifying a nucleic acid molecule encoding a protein comprising at least one immunoglobulin constant domain-like region by (a-i) replacing the nucleotides encoding at least one amino acid, preferably an uncharged amino acid, in the loop separating the C strand from the D strand with nucleotides encoding a charged amino acid selected from the group consisting of Arg, Lys, His, Glu and Asp and/or replacing the nucleotides encoding at least one amino acid, preferably an uncharged amino acid, in the helix connecting the E strand with the F strand with nucleotides encoding a charged amino acid selected from the group consisting of Arg, Lys, His, Glu and Asp; (a-ii) replacing the nucleotides encoding at least one amino acid not having a side chain that can form a hydrogen bond in the loop separating the C strand fr

Abstract: The invention relates to a method for optimizing the biophysical properties of molecules and derivatives of the Ig superfamily. The method is characterized in that as yet unrecognized helical structural elements with unknown structural, stability and folding roles have been identified as important determinants of correct and efficient structuring of antibody domains. The novel process for positively influencing the antibody properties and properties of other proteins that have the Ig folding pattern now consists of optimizing the properties of the short helical elements and in the transplantation of these elements between Ig domains.