过氧化氢酶 来源于牛肝脏

Research Area: Cell Signaling

Catalase from bovine liver is a tetramer consisting of 4 equal subunits each with a 60 kDa molecular weight. Each of these subunits contains iron bound to a protoheme IX group. The enzyme will also strongly bind to NADP, where NADP and the heme group are within 13.7 angstroms.

过氧化氢酶作为天然抗氧化剂，可用于研究活性氧物质对基因表达和凋亡的作用。它还被用于保护蛋白质、脂质和核酸免受氧化损伤。 工业上，过氧化氢酶已被用于去除添加至牛奶和奶酪中以及纺织品漂白使用的过氧化氢，并用于检查其对DNA修复大肠杆菌突变体活力的阳性效应。

过氧化氢酶活性在4.0-8.5的pH范围内保持恒定。酶活性可被3-氨基-1-H-1,2,4三唑、氰化物、叠氮化物、羟胺、溴化氰、2-巯基乙醇、二硫苏糖醇、邻联茴香胺和硝酸盐抑制。过氧化氢酶与抗坏血酸盐或抗坏血酸盐/Cu²⁺ 一起孵育，可导致过氧化氢酶分子的降解。

Catalase, an antioxidant enzyme found in all aerobic organisms, catalyzes the degradation of hydrogen peroxide, a byproduct of metabolic processes, into less harmful water and oxygen. It can also react with alkylhydrogen peroxides, such as methylperoxide and ethylperoxide and the second H₂O₂ molecule can be replaced by methanol, ethanol, propanol, formate and nitrate as a hydrogen donor. Catalase enzyme uses either iron (Fe) or manganese (Mn) as cofactor, and are classified as Fe-CAT or Mn-CAT.

过氧化氢酶溶液不可冷冻。 冷冻溶液将导致酶活性损失50-70％。

一单位酶可在pH7.0、25℃下每分钟分解1.0 μM的H₂O₂，通过测量A₂₄₀的下降速率可知H₂O₂浓度从10.3降至9.2 mM。