*6.1.3. Catalase (CAT)*

Catalase (EC 1.11.1.6) is a tetrameric haem-enzyme consisting of 4 identical tetrahedrally arranged subunits of 60 kDa. It is highly efficient that it is difficult to be saturated by H202 at any concentration [81]. Catalase reacts with H202 to form water and molecular oxygen, a less/ nontoxic product. Catalase protects cells from hydrogen peroxide generated within them. It is actively involved in the HIV disease progression and may serve as one of the marker enzymes where it augments glutathione, SOD and other antioxidants. Serum catalase is known to increase as HIV disease progresses [82, 83].
