BIOSYNTHESIS AND PURIFICATION OF V AND W ANTIGENS IN PASTEURELLA PESTIS

Abstract

The sparation and purification of V and W antigens are described. The methods that gave the best results were: The precipitation of both antigens from the supernatant fluid of a 36 C grown culture of strain M23 by use of ammonium sulfate. Chromatography on DEAE cellulose. V antigen was eluted with 0.1 M NaCl and W antigen with 0.5 M NaCl. Recycling both antigens on DEAE cellulose resulted in a sample contain ing approximately 20 units of V antigen per milligram of protein (100 fold purification) and no W antigen, and a senple containing 600 units of W antigen per milligram of protein (1000 fold purification) and no V antigen. V antigen is a protein with a molecular weight of 90,000 and W antigen is a lipoprotein with a molecular weight of 145,000. Both antigens were stable at 60 C, but not at 80 C, for 30 minutes, W antigens, but not V, was lost upon extensive dialysis against distilled water or pervaporation. Both antigens were reduced in titer by prolonged storage at 5 C or by lyophilization, but not by storage at -20 C.. Based on the use of rabbit antisera containing only V antibody or only W antibody, the conclusion was drawn that V antibody, but not W antibody, can protect mice against plague.