Partial Purification and Properties of S - Adenosyl - L - Methionine : ( Qtetrahydroprotoberberine - Cis - N - Methyltransferase from Suspension - Cultured Cells of Eschscholtzia and Corydalis
نویسندگان
چکیده
An enzyme has been found in different species of isoquinoline alkaloid-producing plant cell cultures which specifically N-methylates certain (S)-tetrahydroprotoberberine alkaloids such as (S)-canadine and (S)-stylopine at the expense of S-adenosyl-L-methionine (SAM). It was partiaily purified (90-fold) from Eschscholtzia calijornica cell suspension cultures and characterized. The enzyme has a pH optimum of 8.9, a temperature optimum at 40” and a M, of about 78 000 + 10%. The K, for (S)-canadine was determined to be 6.4 PM, for (S)-stylopine 3.1 PM and for SAM 12 PM. The enzyme is inhibited by S-adenosyl-L-homocysteine (SAH) with a Ki of 24 PM.
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