The o‐diphenol oxidase activity of arthropod hemocyanin

FEBS Letters

Beltramini, M.¹  Salvato, B.¹  Di Muro, P.¹  Zlateva, T.¹ 

[1] Department of Biology and CNR Centre for the Physiology and Biochemistry of Metalloproteins, University of Padova, Via Trieste 75, I-35135 Padova, Italy

关键词: Hemocyanin;    Copper active site;    Dioxygen;    Catechol;    (Carcinus maenas);    (Homarus americanus);    Hc;    hemocyanin;    Ty;    tyrosinase;   

DOI  :  10.1016/0014-5793(96)00326-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Arthropod hemocyanin (isolated from the crab Carcinus maenas and the lobster Homarus americanus) is usually referred to as an oxygen transport-storage protein. The protein, however, also catalyses with low efficiency the oxidation of o-diphenol to quinone, similarly to tyrosinase (monophenol,o-diphenol: oxygen oxidoreductase). The enzymatic parameters of hemocyanin are affected by the aggregation state of the protein; namely V _max exhibited by a dissociated subunit is one order of magnitude greater than that of aggregated species. The reaction velocity is increased by the presence of perchlorate, an anion of the Hofmeister series. The results are also discussed on the basis of active site accessibility in comparison with tyrosinase.

【 授权许可】

Unknown