METHOD FOR PRODUCING RECOMBINANT THROMBIN
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.
1 . A method for producing folded prethrombin or a derivative thereof, wherein inclusion bodies which comprise non-folded prethrombin or a derivative thereof are solubilized in a solubilization buffer which comprises at least one chaotropic compound and at least one organic disulphide compound, and the solubilized prethrombin or derivative thereof is then renatured in a renaturing buffer which contains at least one reducing agent, at least one folding assistant and divalent cations, both the solubilization buffer and the renaturing buffer comprising no detergent.
2 . The method according to claim 1 , wherein the disulphide compound is glutathione disulphide.
3 . The method according to claim 1 or 2 , wherein the chaotropic compound is chosen from guanidinium salts, iodides, barium salts, thiocyanates, urea and perchlorates.
4 . The method according to claim 1 , wherein the inclusion bodies have been obtained by recombinant expression of prethrombin or a derivative thereof in prokaryotic cells.
5 . The method according to claim 1 , wherein the reducing agent is an organic monosulphide.
6 . The method according to claim 1 , wherein the folding assistant is chosen from arginine and glycerol.
7 . The method according to claim 1 , wherein the folding is carried out in a pulse renaturing method.
8 . The method according to claim 1 , wherein the renatured prethrombin or derivative is purified by chromatography.
9 . The method according to claim 8 , wherein the purification is carried out by hydrophobic interaction chromatography (HIC).
10 . A method for producing thrombin and/or α-thrombin or a derivative thereof, wherein the renatured prethrombin produced according to claim 1 is converted into thrombin and/or α-thrombin or the derivative thereof by enzymatic proteolysis, in particular with ecarin.
11 . The method according to claim 10 , wherein the thrombin and/or α-thrombin or derivative thereof is purified by chromatography after the proteolysis.
12 . The method according to claim 11 , wherein the purification is carried out by hydrophobic interaction chromatography (HIC).
13 . A solution comprising folded prethrombin, folded thrombin and/or folded α-thrombin, or a derivative thereof, obtainable by a method according to claim 1 .
14 . The method according to claim 3 , wherein the chaotropic compound is chosen from guanidinium hydrochloride and guanidinium thiocyanate.
15 . The method of claim 10 , wherein the conversion by enzymatic proteolysis is done with ecarin.