细胞色素P450 人

Research Area: Immuno and CKS
Cytochromes are a type of protein belonging to superfamilies containing heme as a cofactor, making them hemoproteins. These proteins, also known as CYPs, serve as substrates in enzymatic reactions. The term "P450" originates from the enzyme′s maximum optical density peak at 450 nm when in its reduced state combined with carbon monoxide. Cytochromes are present in various tissues throughout the human body, with a predominant presence in intestinal and hepatic tissues.

Cytochrome P450 human has been used in aflatoxin B1 (AFB1) metabolites analysis to study its effects on AFB1-induced cytotoxicity and micronuclei formation in human hepatocyte (L-02) and human lymphoblastoid (TK6) cells. It has also been used in cell-free cytochrome P4501B1 (CYP1B1) inhibition assays.

Cytochromes play a crucial role in metabolizing a wide range of xenobiotic compounds and are engaged in diverse functions such as steroid metabolism, deactivation of drugs and procarcinogens, metabolism of fatty acids, detoxification of xenobiotic substances, and breakdown of exogenous compounds. It facilitates the oxidation of substances using iron. CYP is well-established that changes in CYP enzymes often occur as a common consequence of immune system activation following infection and inflammation. Despite the overlapping effects of cytokines, the activity of human P450s is independently regulated in infection and inflammation.

细胞色素P450是异质性同工酶家族，其主要功能是氧化小分子，发挥中间代谢（如脂肪酸）功能和对外源性化合物（药物或毒素）进行解毒。有些同工型具有有限的底物特异性，而其他同工酶则比较混杂。CYP1A1亚型催化乙氧基试卤灵的7-脱乙基。细胞色素P450(CYP)在外源物解毒、细胞代谢和稳态中起重要作用。药物相互作用的一种主要机制就是激活或抑制这类酶。CYP酶可被多种外源物和内源底物经由受体依赖途径转录激活。基于代谢的药物相互作用主要影响就是抑制这类酶，许多化疗药物可通过抑制或诱导细胞色素P450酶系引发药物互作。

Solution in 100 mM potassium phosphate buffer, pH 7.4.

Microsomes containing human CYP1B1 and recombinant human NADPH-P450 reductase.

Tested for the ability to catalyze the 7-deethylation of ethoxyresorufin.

One unit will reduce 1 nanomole of cytochrome C per minute at pH 7.4 at 37 deg C.