Gosset Molecular Classification
Enzyme, Metalloprotein
Other Names
CA5, CA5AD, CAV, CAVA, GS1-21A4.1, carbonic anhydrase VA/VA-mitochondrial
Disease Roles
Carbonic anhydrase 5A, mitochondrial Overview
Carbonic anhydrase 5A, mitochondrial (CA5A) is a zinc metalloenzyme that catalyzes the reversible hydration of carbon dioxide to bicarbonate within mitochondria. It plays a crucial role in providing bicarbonate for carbamoyl phosphate synthetase I (urea cycle) and pyruvate carboxylase (gluconeogenesis), among other enzymes. CA5A is primarily expressed in the liver, and its deficiency leads to hyperammonaemia due to impaired ammonia detoxification. Treatment includes carglumic acid administration to support the urea cycle.
Mechanism of Action
Carglumic acid enhances the activity of carbamoyl phosphate synthetase I, bypassing the need for CA5A-produced bicarbonate in the urea cycle and thus reducing hyperammonaemia.
Biological Functions
Catalysis
Carbon dioxide hydration
Bicarbonate production
Ureagenesis support
Gluconeogenesis support
Acid-base balance
Disease Associations
Carbonic anhydrase VA deficiency
Hyperammonaemia
Safety Considerations
- Potential for hyperammonaemia recurrence despite treatment
- Varied efficacy across patients due to residual enzyme activity
- Need for careful monitoring to prevent metabolic decompensation
Interacting Drugs
Carglumic acid