Novel inhibition mechanism of Bacillus cereus sphingomyelinase by beryllium fluoride.
Phosphate analogs have been known to inhibit competitively various phosphatases and phospholipase C and D. We found for the first time that only beryllium fluoride (BeF(x)) among the phosphate analogs studied inhibits Bacillus cereus sphingomyelinase (SMase) activity. The active inhibitory species proved to be not BeF(3)(-) but BeF(2) by the measurement of SMase activity and of (19)F NMR spectroscopy in the presence of a fixed concentration of BeCl(2) and different concentrations of NaF, although both the species have been reported for other kinds of enzymes. The result of kinetic experiment also indicated that the BeF(x) binds in the vicinity of the essential binding site for the substrate and that the Mg(2+) binding to SMase is essential for the binding of BeF(x) to the enzyme.
Fujii
Shinobu
S
Department of Biochemistry, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
Nagata
Michiyo
M
Morita
Michio
M
Minoura
Katsuhiko
K
Tsukamoto
Kikuo
K
Ikezawa
Hiroh
H
Ikeda
Kiyoshi
K
D001409:Bacillus cereus / Q000201:enzymology*; D001608:Beryllium / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D013108:Sphingomyelin Phosphodiesterase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism
D004791:Enzyme Inhibitors; D010710:Phosphates; D003035:Cobalt; D008345:Manganese; C035982:beryllium fluoride; D013108:Sphingomyelin Phosphodiesterase; D001608:Beryllium; D005459:Fluorides