PURPOSE: To enable the mass-production of arginine deiminase by transforming E.coli with an expression vector containing a DNA sequence coding an arginine deiminase gene and culturing the transformed E.coli under prescribed condition.
CONSTITUTION: An expression vector bonded with a fragment of tac promoter, a fragment of the replication starting point (ori) of plasmid puc18 and a DNA fragment coding the amino acid sequence of arginine deiminase or its analog is constructed beforehand. E.coli is transformed by using the expression vector and the transformed E.coli is cultured. The expressed arginine deiminase or its analog is recovered and purified. The obtained arginine deiminase has an activity comparable to that of arginine deiminase originated from mycoplasma and is an antitumor enzyme effectively utilizable as a carcinostatic agent.
AOSHIMA YOSHIO