Methods for reducing gluconoylation of proteins
The present invention relates to methods of preventing glyconoylation of polypeptides produced in micororganisms.
1. A method for reducing gluconoylation of a heterologous polypeptide expressed in E. coli , wherein said heterologous polypeptide is human IL-18, said method comprising growing said E. coli in rich culture medium, wherein the amount of gluconoylation on said human IL-18 is reduced as compared to E. coli grown in minimal medium.
2. The method of claim 1 , wherein the E. coli does not demonstrate significant 6-phosphogluconolactonase activity when grown in minimal medium.
3. The method of claim 1 , wherein the E. coli is B strain.
4. The method of claim 1 , wherein the rich culture medium comprises a complex nitrogen source.
5. The method of claim 4 , wherein the rich culture medium is capable of maintaining cell growth at ratio of 1:1 for concentration of complex nitrogen source to cell density.
6. The method of claim 4 , wherein the complex nitrogen source comprises tryptone.
7. The method of claim 4 , wherein the complex nitrogen source comprises peptone.
8. The method of claim 4 , wherein the complex nitrogen source comprises yeast extract.
9. The method of claim 1 , wherein the culture medium is Superbroth.
10. The method of claim 9 , wherein the Superbroth medium is doubly concentrated.