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DNA methylation by wheat cytosine DNA methyltransferase: Modulation by protease inhibitor E‐64
Author(s) -
Vlasova Tatyana I.,
Vanyushin Boris F.
Publication year - 1998
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549800202512
Subject(s) - methyltransferase , enzyme , biochemistry , dna methyltransferase , dna , cytosine , serine protease , protease , chemistry , microbiology and biotechnology , dnmt1 , methylation , cysteine , enzyme assay , proteases , biology
Cytosine DNA methyltransferase isolated from wheat seedlings and purified in the presence of metalloprotease and serine protease inhibitors has molecular mass and specific activity equal to about 85 kDa and 250 units/mg protein, respectively. Apparent Km for AdoMet& and [I]50 for AdoHcy values are about 6 μM and 12 μM, respectively. The enzyme is active in wide pH range (pH 5.5‐8.5) and is inhibited by NaCl. The enzyme rapidly loses its methyltransferase activity in the absence of substrates. Using the cysteine protease inhibitor E‐64 it has been shown that rapid enzyme inactivation is caused by disappearance of essential enzyme SH‐groups but is not due to proteolytic enzyme cleavage.