Solubilization of the factor required for polymerization of flagellin into P-filament

Abstract

1. 1. A membrane fraction derived from deflagellated cells of a Salmonella strain initiates polymerization of flagellin into “P-filaments” which differ in many respects from flagellar filaments 1. 2. 2. When the membrane fraction was treated with 1% (w/v) Tween-20, it was partially solubilized, giving a fraction which was effective for initiation of polymerization. 3. 3. The soluble fraction contained protein, (poly-)saccharide and organic phosphorus presumably originating from phospholipid. The weight ratio between protein and saccharide was about 1:1.5 and that between organic phosphorus and saccharide was about 1:10. 4. 4. These components appeared to be tightly associated into a complex, which had an s 20, w o value of 4.2. 5. 5. On the addition of the soluble fraction practically 100% of the total flagellin was polymerized into P-filaments. When P-filaments were washed with distilled water, they contained only trace amounts of saccharide and organic phosphorus.