Method of producing interleukin-2
AssigneeTakeda Chemical Industries, Ltd.
InventorsKazuaki Kitano, Shigeru Fujimoto
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Abstract
The present invention provides an improvement in a method for producing physiologically active proteins by cultivating Escherichia coli having an expression vector which contains a structural gene for such proteins at the downstream end of the translational starting codon. The method comprises cultivating the Escherichia coli in a medium containing (1) an iron ion source, a manganese ion source or a mixture thereof and (2) a nitrogen source derived from natural origin. The advantage of this method is an increase in the yield of physiologically active proteins substantially free of methionine (corresponding to translational starting codon ATG) at the N-terminus.
Claims15
In a method for producing the physiologically active protein interleukin-2 by cultivating Escherichia coli having an expression vector which contains the structural gene for the protein at the downstream end of a translational starting codon, the improvement comprising cultivating the Escherichia coli in a medium to which is added:
- (1) an iron ion source, a manganese ion source, or a mixture thereof, at a concentration of from about 1.times.10.sup.-6 to about 1.times.10.sup.-3 moles per liter;
- and
- (2) a nitrogen source derived from natural original at a concentration of from about 1 gram per liter to about 50 grams per liter;
- to increase the yield of the protein, free of methionine corresponding to a translational starting codon ATG at the N-terminus.
Dependencies are inferred from the claim text.