RECOMBINANT HUMAN LYMPHOTOXIN - EXPRESSION IN ESCHERICHIA-COLI, PURIFICATION, AND SOME PROPERTIES

Biosynthesis of human lymphotoxin lacking 21 amino acid residues was s tudied in the recombinant strain Escherichia coli SG20050/pLT21. The m ain content of the protein was found to be soluble and predominantly l ocated in the cytoplasm of E. coli. Synthesis of soluble recombinant l ymphotoxin was maximal under cultivation in Luria broth at 32 degrees C for 24 h. A method for isolation and purification of the recombinant protein from E. coli was elaborated. The procedure includes gd filtra tion on Sephadex G-150 and ion-exchange chromatography on DEAE- and CM -Sephadex. The protein was obtained with 97-fold purification and fina l yield of 62%. The specific activity was 10(8) units per mg protein. Some physicochemical properties of the protein were investigated.