Abstract: The invention relates to a method for producing folded prethrombin, wherein inclusion bodies, which contain unfolded prethrombin or a derivative thereof, are solubilized in a solubilization buffer containing at least one chaotropic compound and at least one organic disulfide compound. The invention further relates to methods for producing thrombin and a-thrombin and derivatives thereof. The invention also relates to solutions that contain folded proteins, which can be produced by the methods according to the invention.

Abstract: A process for the production of a naturally folded eukaryotic polypeptide containing two or several cysteines linked by disulfide bridges by a) culturing prokaryotic cells in which the said prokaryotic cells contain an expression vector which codes for the said polypeptide which contains a prokaryotic signal sequence at the N-terminus, b) secreting the polypeptide into the periplasm or the medium, c) cleaving the signal sequence and isolating the polypeptide from the periplasm or the medium, which is characterized in that a nucleic acid coding for a molecular chaperone is additionally expressed in the said prokaryotic cell and the chaperone is secreted into the periplasm, is suitable for the recombinant production of polypeptides in prokaryotes in a high yield.

Abstract: A process produces a water-soluble, naturally folded eukaryotic polypeptide containing two or several cysteines linked by disulfide bridges. This process involves culturing prokaryotic cells, a) in which the prokaryotic cells contain an expression vector which encodes the polypeptide which contains a prokaryotic signal sequence at the N-terminus, b) under conditions under which the polypeptide is secreted into the periplasm or the medium, c) cleaving the signal sequence and isolating the polypeptide from the periplasm or the medium. In this process, the culturing is carried out in the presence of arginine or a compound of the formula I R2—CO—NR1 (I) in which R and R1 represent hydrogen or a saturated or unsaturated branched or unbranched C1-C4 alkyl chain and R2 represents hydrogen, NHR1 or a saturated or unsaturated branched or unbranched C1-C3 alkyl chain, is suitable for the recombinant production of polypeptides in prokaryotes in a high yield.