22''R''-Hydroxycholesterol, or (3β)-cholest-5-ene-3,22-diol is an endogenous,

metabolic intermediate Metabolic intermediates are molecules that are the precursors or metabolites of biologically significant molecules. Although these intermediates are of relatively minor direct importance to cellular function, they can play important roles in the ...

in the biosynthesis of the

steroid hormone A steroid hormone is a steroid that acts as a hormone. Steroid hormones can be grouped into two classes: corticosteroids (typically made in the adrenal cortex, hence ''cortico-'') and sex steroids (typically made in the gonads or placenta). Withi ...

s from

cholesterol Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...

. Cholesterol ((3β)-cholest-5-en-3-ol) is hydroxylated by

cholesterol side-chain cleavage enzyme Cholesterol side-chain cleavage enzyme is commonly referred to as P450scc, where "scc" is an acronym for side-chain cleavage. P450scc is a mitochondrial enzyme that catalyzes conversion of cholesterol to pregnenolone. This is the first reactio ...

(P450scc) to form 22''R''-hydroxycholesterol, which is subsequently hydroxylated again by P450scc to form 20α,22''R''-dihydroxycholesterol, and finally the bond between carbons 20 and 22 is cleaved by P450scc to form

pregnenolone Pregnenolone (P5), or pregn-5-en-3β-ol-20-one, is an endogenous steroid and precursor/ metabolic intermediate in the biosynthesis of most of the steroid hormones, including the progestogens, androgens, estrogens, glucocorticoids, and mineraloc ...

((3β)-3-hydroxypregn-5-en-20-one), the

precursor Precursor or Precursors may refer to: * Precursor (religion), a forerunner, predecessor ** The Precursor, John the Baptist Science and technology * Precursor (bird), a hypothesized genus of fossil birds that was composed of fossilized parts of u ...

to the steroid hormones. It is an agonist of the

liver X receptor The liver X receptor (LXR) is a member of the nuclear receptor family of transcription factors and is closely related to nuclear receptors such as the PPARs, FXR and RXR. Liver X receptors (LXRs) are important regulators of cholesterol, fat ...

References

Cholestanes Sterols {{Steroid-stub

See also

References