Abstract: The invention concerns recombinant proteinase K. Furthermore a method for producing recombinant proteinase K is disclosed, which is characterized in that a) a host cell is transformed with a recombinant nucleic acid which codes for the zymogenic precursor of proteinase K, b) the host cell is cultured in such a manner that the zymogenic precursor of proteinase K is formed in the form of inclusion bodies in the host cell, c) the inclusion bodies are isolated and natured under conditions which result in the formation of the protease part of the zymogenic precursor in its natural conformation, d) the natured proteinase K is activated and purified.

Abstract: The present invention relates to the use of substituted imidazolium salts for the renaturation, for the decrease of aggregation and/or for the increase of the thermal stability of proteins as well as to a method for the renaturation of proteins, for the decrease of the aggregation and/or for the increase of the thermal stability of proteins as well as to renatured proteins prepared by means of the method according to the invention. In the method according to the invention, the proteins to be treated are contacted with a liquid renaturation medium containing substituted imidazolium salts.

Abstract: A chimeric polypeptide has a first and a second polypeptide chain chemically linked via 1 to 3 cysteine-based disulfide bridges. The first polypeptide chain consists of 1 to 3 cysteines and 4 to 12 basic amino acids preferably selected from the group consisting of arginine, lysine and ornithine. The second polypeptide chain consists of 1 to 3 cysteines and 4 to 12 acidic amino acids selected from the group consisting of glutamate and aspartate. Each polypeptide chain is linked at its C- or N-terminus to a biologically active compound, and is useful as a multimeric pharmaceutical agent.