Studies on a Lipoic Acid-Activating System

Summary of Fractionation of 8. faecalis &&-act FrSdi0ll Diluted extract. PP PS PP-1. PS-2. PS-28 PS-2B PS-2B (heated). ...... ...... ...... ...... ...... ...... ...... - . . - -- - VOlllllW Protein ml. mg. 500 10,250 40 440 550 3,900 30 111 63 227 31 139 31 130 31 63 - - -- - Activity units )W mg. of protein o.s5* 18.0 2.4 21.0 18.5 27.3 28.0 57.0 RWWXy per cent 100 92 106 27t 49 44 42 40 * This value varied from 0.65 to 1.7 in different preparations. t The recovery in some instances was as high as 50 per cent. were added slowly with stirring 2.5 ml. of 50 per cent TCA. The precipi- tate was collected by centrifugation and suspended in 7.5 ml. of deionized water. The suspension was adjusted to pH 4.7 with 0.1 N potassium hy- droxide and then centrifuged. The supernatant fluid was dialyzed for 4 hours with stirring against deionized water. The recovery of Fraction PS-2B activity was 34 per cent (8.4 mg. of protein, specific activity 96).