IMP dehydrogenase

IMP dehydrogenase (IMPDH) is an enzyme that plays a crucial role in the purine metabolism pathway, specifically in the synthesis of guanine nucleotides. This enzyme catalyzes the conversion of inosine monophosphate (IMP) to xanthosine monophosphate (XMP), a key step in the production of guanosine triphosphate (GTP).

Function

IMPDH is a tetrameric enzyme that catalyzes the oxidation and dehydrogenation of IMP to XMP, with the concurrent reduction of nicotinamide adenine dinucleotide (NAD+) to nicotinamide adenine dinucleotide hydrogen (NADH). This reaction is a rate-limiting step in the de novo synthesis of guanine nucleotides.

Clinical significance

Due to its role in the synthesis of guanine nucleotides, IMPDH is a target for several antiviral, immunosuppressive, and anticancer drugs. Inhibition of IMPDH can lead to a decrease in the synthesis of DNA and RNA, which can inhibit the growth of rapidly dividing cells, such as cancer cells or cells infected with a virus.

Genetics

In humans, two genes, IMPDH1 and IMPDH2, encode for IMPDH. Mutations in these genes can lead to diseases such as retinitis pigmentosa and Leber's congenital amaurosis.

See also

• Purine metabolism
• Guanine nucleotide
• Inosine monophosphate
• Xanthosine monophosphate
• Guanosine triphosphate

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