P450reduktase

P450reduktase, also known as NADPH-cytochrom P450 reduktase or CPR, is a crucial enzyme found in most aerobic organisms. It plays a vital role in the electron transport chain for the cytochrome P450 superfamily of enzymes. CPR acts as a molecular bridge, transferring electrons from the NADPH cofactor to the heme iron center of P450 enzymes. This electron transfer is essential for the catalytic activity of P450s, which are involved in a wide array of metabolic processes.

In mammals, CPR is a membrane-bound flavoprotein located primarily in the endoplasmic reticulum. It possesses two redox-active flavin prosthetic groups: FMN and FAD. The enzyme first binds NADPH, leading to the reduction of FAD. This reduced FAD then reduces FMN, which in turn transfers electrons to the P450 enzyme. This sequential electron transfer mechanism ensures efficient and controlled delivery of reducing equivalents.

The P450 system, with CPR as a key component, is responsible for the metabolism of numerous endogenous and exogenous compounds. This includes the synthesis of steroid hormones, bile acids, and prostaglandins, as well as the detoxification and metabolism of xenobiotics such as drugs, environmental pollutants, and carcinogens. Due to its central role in drug metabolism, CPR is a significant target for drug interactions and influences drug efficacy and toxicity. Genetic variations in the CPR gene can also lead to altered metabolic profiles and potentially affect an individual's susceptibility to certain diseases.