Isolation of the met-derivative intermediate in the catalase-like activity of deoxygenated Octopus vulgaris hemocyanin
| Autor: | Luigi Casella, Mariano Beltramini, Laura Santagostini, Theodora Zlateva, Benedetto Salvato, Luigi Bubacco |
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| Rok vydání: | 1998 |
| Předmět: |
Enzymatic activity
biology Active site Chemical modification hydrogen peroxide chemical and pharmacologic phenomena Reaction intermediate Photochemistry Hemocyanin Biochemistry Medicinal chemistry Metal site Azide Inorganic Chemistry chemistry.chemical_compound chemistry Catalase biology.protein Sodium azide Hydrogen peroxide Derivative (chemistry) |
| Zdroj: | Journal of Inorganic Biochemistry. 72:211-215 |
| ISSN: | 0162-0134 |
| DOI: | 10.1016/s0162-0134(98)10082-x |
| Popis: | The deoxygenated form [Cu(I)Cu(I)] of molluscan hemocyanin exhibits a catalase-like activity. The initial formation of the met-derivative [Cu(II)Cu(II)] is followed by reaction of a second molecule of hydrogen peroxide, leading to oxy-hemocyanin. Sodium azide, a ligand that is also able to coordinate to the binuclear cupric site of met-hemocyanin, shows competitive inhibition of the regeneration reaction by hydrogen peroxide. Therefore, in the presence of an excess of azide the reduction of met-hemocyanin by hydrogen peroxide is prevented and the met-hemocyanin azide complex becomes the main reaction product. After removal of excess reactants, the derivative obtained exhibits the characteristic features of met-hemocyanin. The preparation of this derivative by the present method requires a shorter time and is carried out under milder chemical conditions than those used in other methods previously reported in the literature. Furthermore, this new method is based on trapping of a reaction intermediate and not on the chemical modification of the protein after the labilization of the active site. |
| Databáze: | OpenAIRE |
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