Hemocyanin (Hc)

Hemocyanins are large, multi-subunit, copper-containing proteins that facilitate oxygen transport in the hemolymph of various invertebrates, including mollusks and arthropods (Source: UniProt). Unlike the iron-based hemoglobin found in vertebrates, hemocyanins utilize two copper atoms to reversibly bind a single oxygen molecule, resulting in a blue coloration when oxygenated (Source: Wikipedia). In clinical medicine, Keyhole Limpet Hemocyanin (KLH), derived from the marine gastropod Megathura crenulata, is utilized as a powerful immunostimulant and vaccine carrier (Source: PubChem). It is highly effective as a treatment for superficial bladder cancer and serves as a standard carrier protein for haptens in immunological research and vaccine development due to its ability to elicit a robust T-cell dependent immune response (Source: PubMed). Its therapeutic utility stems from its high molecular weight and foreign nature, which makes it one of the most immunogenic proteins known (Source: StatPearls). Furthermore, hemocyanins are being investigated for their potential anti-tumor properties and as diagnostic tools to assess immune competence in patients (Source: NIH).

Other names

Keyhole limpet hemocyaninKLHMolluscan hemocyaninArthropod hemocyaninMegathura crenulata hemocyaninCopper-based oxygen carrier

Hemocyanin, particularly Keyhole Limpet Hemocyanin (KLH), acts as a potent foreign antigen that stimulates a robust Th1-type cellular immune response and antibody production. In the treatment of bladder cancer, it induces a local inflammatory response and recruitment of cytotoxic T cells to the tumor site (Source: PubMed, PMID: 11563487).