Hemocyanin

Hemocyanin is a copper protein capable of transporting oxygen molecules. It exists dissolved in the hemolymph of mollusks and arthropods. Its abundance ranges from a few percent to 10% of the hemolymph, and accounts for 90-95% of the hemolymph proteins. The number of copper ions per hemocyanin molecule varies by species, but the copper content is fairly constant at about 0.18% in arthropods and about 0.25% in mollusks. The molecular weight of hemocyanin in the snail Helix pomatia is 8.91 x 10 ⁶ , and that of the crab Cancer magistev is 9.5 x 10 ⁵ , and varies by species, but all are large molecules. It binds one molecule of oxygen to two copper atoms. When hemocyanin is dialyzed against an aqueous solution of potassium cyanide, the copper ions are released and it loses its oxygen-binding ability, but the activity is restored by adding Cu ⁺ . [See alternative term] Hemoglobin

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

酸素分子の運搬能を有する銅タンパク質．軟体動物，節足動物の血リンパ(hemolymph)に溶解して存在する．存在量は血リンパの数％～10％，また血リンパタンパク質の90～95％ を占める．ヘモシアニン1分子当たりの銅イオン数は種によって異なるが，銅含量は節足動物で約0.18％，軟体動物で約0.25％ でほぼ一定している．分子量はカタツムリHelix pomatiaのヘモシアニンで8.91×10⁶，カニCancer magistevで9.5×10⁵，種によって差があるがいずれも巨大分子である．2個の銅原子に対して1分子の酸素を結合する．銅イオンはヘモシアニンをシアン化カリウム水溶液に対して透析すると離脱し，酸素結合能が失われるが，これに Cu^＋ を添加すれば活性は復元する．[別用語参照]ヘモグロビン

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