<p>Haemocyanins are copper-containing oxygen transport proteins found in the haemolymph of many invertebrates. They are divided into 2 main groups, arthropodan and molluscan. These have structurally similar oxygen-binding centres, which are similar to the oxygen-binding centre of tyrosinases [<cite idref="PUB00004010"/>], but their quaternary structures are arranged differently. The arthropodan proteins exist as hexamers comprising 3 heterogeneous subunits (a, b and c) and possess 1 oxygen-binding centre per subunit; and the molluscan proteins exist as cylindrical oligomers of 10 to 20 subunits and possess 7 or 8 oxygen-binding centres per subunit [<cite idref="PUB00000297"/>]. Although the proteins have similar amino acid compositions, the only real similarity in their primary sequences is in the region corresponding to the second copper-binding domain, which also shows similarity to the copper-binding domain of tyrosinases [<cite idref="PUB00004010"/>]. </p><p>Larval storage proteins (LSP) [<cite idref="PUB00002522"/>] are proteins from the hemolymph of insects, which may serve as a store of amino acids for synthesis of adult proteins. There are two classes of LSP's, arylphorins, which are rich in aromatic amino acids, and methionine-rich LSP's. LSP's forms hexameric complexes. LSP's are structurally related to arthropods hemocyanins.</p> Hemocyanin, C-terminal