Effect of Selected Phytotoxins from Guanomyces polythrix on the Calmodulin-Dependent Activity of the Enzymes cAMP Phosphodiesterase and NAD-Kinase
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- 作者：Rachel Mata ; Alicia Gamboa ; Martha Macias ; Sandra Santillá ; n ; Miguel Ulloa ; and Marí ; a del Carmé ; n Gonzá ; lez
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2003
- 出版时间：July 30, 2003
- 年：2003
- 卷：51
- 期：16
- 页码：4559 - 4562
- 全文大小：56K
- 年卷期：v.51,no.16(July 30, 2003)
- ISSN：1520-5118
文摘
The effect of a series of phytotoxins isolated from the fungus Guanomyces polytrix on calmodulin(CaM)-dependent nicotinamide adenine dinucleotide kinase (NADK) and CaM-dependent cyclicnucleotide phosphodiesterase (PDE) activities was investigated. The results indicated that (2S,3S)-5-hydroxy-6,8-dimethoxy-2,3-dimethyl-4H-2,3-dihydronaphtho[2,3-b]-pyran-4-one, (2S,3S)-5-hydroxy-6,8,10-trimethoxy-2,3-dimethyl-4H-2,3-dihydro-naphtho[2,3-b]-pyran-4-one, (2S,3R)-5-hydroxy-6,8-dimethoxy-2,3-dimethyl-2,3-dihydro-4H-naphtho[2,3-b]-pyran-4-one, (2S,3R)-5-hydroxy-6,8,10-trime-thoxy-2,3-dimethyl-2,3-dihydro-4H-naphtho[2,3-b]-pyran-4-one, 5-hydro-xy-6,8-dimethoxy-2,3-dimethyl-4H-naphtho[2,3-b]-pyran-4-one, rubrofusarin B, and ergosta-4,6,8(14),22-tetraen-3-one inhibited theactivation of both target enzymes in the presence of CaM. On the other hand, (2S)-5-hydroxy-6,8-dimethoxy-2-methyl-4H-2,3-dihydronaphtho[2,3-b]-pyran-4-one and (2S)-5-hydroxy-6,8,10-trimethoxy-2-methyl-4H-2,3-dihydronaphtho-[2,3-b]-pyran-4-one inhibited the activation of PDE and the basalactivity of NADK. Thus, these phytotoxins are CaM inhibitors and may exert their phytotoxic actionby inhibiting the CaM-dependent process, although they could also interfere with other cellularmetabolic phenomena. This is the first report of the use of the NADK assay to detect or quantifyCaM inhibitors, and it could be a valuable tool for studying those CaM isoforms regulating NADK.Keywords: Spinach calmodulin (CaM); bovine-brain calmodulin; cyclic nucleotide phosphodiesterase(PDE); nicotinamide adenine dinucleotide kinase (NADK); Guanomyces polythrix; phytotoxins