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。

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℃条件下每分钟分解1.0 μM的H₂O₂，通过测量A₂₄₀的下降速率可知H₂O₂的浓度从10.3降至9.2 mM。

本品为含0.1%（w/v）百里香酚的过氧化氢酶水悬浮液，活性为40,000-60,000单位/mg蛋白质。为除去百里香酚防腐剂，可以通过离心使过氧化氢酶晶体沉淀，弃去上清液，将沉淀物重悬于水中，然后再次沉淀。该酶溶于50 mM磷酸钾缓冲液中，浓度为1 mg/mL，pH 7.0。