PARTIAL PURIFICATION AND CHARACTERIZATION OF THE CELL-WALL-ASSOCIATED LANATOSIDE 15'-O-ACETYLESTERASE FROM DIGITALIS LANATA SUSPENSION CULTURES

摘要

The cell-wall-associated lanatoside 15'-O-acetylesterase (EC 3.1.1.6) from suspension-cultured Digitalis lanata Ehrh. (Scrophulariaceae) cells was partially purified by cell wall preparation, Mono S ion exchange chromatography and gel filtration on Superose 12. The apparent molecular mass of the enzyme was about 120 kDa as determined by gel filtration. The enzyme has its pi at pH 8.7 and its pH-optimum at around 5.5. The apparent K-m-values for lanatoside A, lanatoside C and alpha-acetyldigoxin were 0.4 mM, 0.6 mM and 0.6 mM, respectively. The enzyme could not be inhibited by p-hydroxymercuribenzoate or eserine and is bound ionically to the cell wall. [References: 32]