Carbonic anhydrase 13 (CA XIII) (CA XIII)

Carbonic anhydrase 13 (CA XIII) is a cytosolic enzyme belonging to the alpha-carbonic anhydrase family, which plays a vital role in the reversible hydration of carbon dioxide to bicarbonate and protons [UniProt, NIH]. This catalytic process is essential for maintaining systemic acid-base homeostasis, regulating pH, and facilitating ion and fluid transport across various tissues [NIH, Wikipedia]. CA XIII is widely expressed in human tissues, including the salivary glands, kidneys, brain, lungs, and reproductive organs, where it is particularly involved in sperm motility and the fertilization process [NIH, PubMed]. In the context of disease, CA XIII has been identified as a potential biomarker; its expression is significantly downregulated in colorectal cancer and it has been shown to suppress bone metastasis in breast cancer [NIH, PubMed]. While it is a target for clinically approved sulfonamide-based inhibitors like acetazolamide and methazolamide, these drugs are non-selective and also inhibit other carbonic anhydrase isoforms [NIH, PubMed]. The high structural similarity between CA XIII and other cytosolic isoforms like CA I and CA II presents a significant challenge for developing selective therapeutic agents [NIH, PubMed]. Consequently, CA XIII remains a subject of intense research for the development of isoform-specific inhibitors to treat conditions such as glaucoma or reproductive disorders while minimizing off-target effects [NIH, PubMed].

Other names

CA13CA-XIIICarbonate dehydratase XIII

Inhibition of the catalytic activity via coordination with the active site zinc ion, which prevents the reversible hydration of carbon dioxide.