Figure 3

Effect of heat activation on the arginase activity of B. anthracis 7702 extracts. Cells were grown on CBA plates at 37°C for 24 h in 5% CO₂ in air, harvested, and extracts prepared as described in Methods. The extracts were assayed with or without heat activation (50–55°C or on ice for 30 minutes, respectively) in the absence (no metal) or presence of 5 mM metal (Co, Mn, or Ni) at pH 6.0 (in MES-buffered arginine) or 9.0 (Tris-buffered arginine). There was no evidence of a buffer effect on activity (data not shown).