STUDIES OF VANADIUM-BROMOPEROXIDASE USING SURFACE AND CORTICAL PROTOPLASTS OF MACROCYSTIS PYRIFERA (PHAEOPHYTA).

Autor: Butler, Alison, Soedjak, Helena S., Polne-Fuller, Miriam, Gibor, Aharon, Boyen, Catherine, Kloareg, Bernard
Předmět:
Zdroj: Journal of Phycology; Sep90, Vol. 26 Issue 3, p589-592, 4p
Abstrakt: Aqueous Tris-SO[SUB4] buffer (pH 8.3) extracts of cortical and surface protoplasts of Macrocystis pyrifera (L.) C. Ag. Catalyzed the bromination of monochlorodimedone (2-chloro-5,5-dimethyl-1,3-dimedone, MCD) in the presence of hydrogen peroxide and bromide. The apparent bromoperoxidase activity as measured by the bromination of MCD was inhibited by the presence of endogenous compounds which are probably polyphenolic compounds (i.e. polymers of phloroglucinol) or other inhibitors. The bromoperoxidase activity of the protoplast extracts increased substantially when the extracts were washed extensively with Tris-SO[SUB4] buffer (pH 8.3) by ultrafiltration. The bromoperoxidase activity of both surface and cortical protoplast extracts was dependent on the presence of vanadium, indicating that the bromoperoxidase present in cortical and surface cells of M. pyrifera is vanadium-bromoperoxidase. Halogenated compounds constitute one of the most significant classes of marine natural products. Since bromoperoxidases are assumed to be involved in the biosynthesis of these compounds, elucidation of the location of BrPO with within the algal tissue is important. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index