A beta-D-fucosidase from Asclepias curassavica latex
1993
Giordani, R. | Lafon, L.
A beta-D-fucosidase was isolated from Asclepias curassavica latex by anion exchange and gel filtration chromatography. The enzyme was purified 136-fold. The enzyme is a monomer and its Mr is close to 50 000. It shows optimal activity at pH 5.5 and at 50 degrees. The enzyme hydrolyses p-nitrophenyl-beta-D-fucopyranoside with apparent K. and Vmax values of 6.58 mM and 304 mM min-1 mg-1 of protein, respectively, at the optimum pH. p-Nitrophenyl-beta-D-fucopyranoside is the best substrate. D(+)-fucose acts as competitive inhibitor with a Ki value of 7.36 mM at pH 5.5. The hypothesis that beta-D-fucosidase represents an enzymatic marker of laticifer differentiation and of the cell wall degradation process is discussed.
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