TLDR: Adrenal ferredoxin is a protein found in humans that plays a role in the synthesis of steroid hormones and other important biological processes.
Adrenal ferredoxin, also known as adrenodoxin (ADX), is a small iron-sulfur protein found in humans. It is encoded by the FDX1 gene. Adrenal ferredoxin is involved in various biological processes, including the synthesis of steroid hormones in steroidogenic tissues like the adrenal glands. It acts as an electron transfer protein in the mitochondrial cytochrome P450 systems.
The first enzyme in this system is adrenodoxin reductase, which carries an FAD molecule. FAD can be reduced by two electrons donated from coenzyme NADPH. These two electrons are then transferred one at a time to adrenodoxin. Adrenodoxin, in turn, reduces mitochondrial cytochrome P450. This oxidation/reduction system is crucial for the synthesis of steroid hormones, as well as the synthesis of vitamin D and bile acids.
Adrenodoxin has been identified in various tissues, but all forms of the protein are identical and not tissue-specific. It plays a vital role in the metabolism of cholesterol and other small molecules, as well as in cellular responses to certain signaling molecules like cAMP and forskolin.
In summary, adrenal ferredoxin is a protein that is involved in the synthesis of steroid hormones and other important biological processes. It acts as an electron transfer protein in the mitochondrial cytochrome P450 systems and plays a crucial role in the metabolism of cholesterol and other small molecules.