IMPDH2

IMPDH2

Inosine-5'-monophosphate dehydrogenase 2 (IMPDH2) is an enzyme that plays a crucial role in the purine nucleotide biosynthesis pathway. It catalyzes the conversion of inosine monophosphate (IMP) to xanthosine monophosphate (XMP), a key step in the synthesis of guanosine monophosphate (GMP).

Function

IMPDH2 is a rate-limiting enzyme in the de novo synthesis of guanine nucleotides. It is essential for the proliferation of lymphocytes and other rapidly dividing cells. The enzyme is encoded by the IMPDH2 gene in humans.

Clinical significance

IMPDH2 is a target for immunosuppressive drugs such as mycophenolate mofetil, which is used to prevent organ transplant rejection. Inhibitors of IMPDH2 are also being investigated for their potential in treating cancer and viral infections.

Structure

The enzyme is a homotetramer, meaning it consists of four identical subunits. Each subunit binds to NAD+ and IMP as substrates. The active site of IMPDH2 is highly conserved across different species, indicating its importance in cellular metabolism.

Regulation

IMPDH2 activity is regulated by feedback inhibition from GTP, the end product of the purine biosynthesis pathway. This regulation ensures a balance between the synthesis of adenine and guanine nucleotides.

Research

Recent studies have focused on the role of IMPDH2 in metabolic disorders and its potential as a biomarker for certain types of cancer. The enzyme's structure has been elucidated using X-ray crystallography, providing insights into its function and mechanism of action.

See also

• Purine metabolism
• Nucleotide synthesis
• Enzyme inhibitors

References

<references/>

External links

• IMPDH2 on WikiMD
• IMPDH2 gene information at NCBI