secalonic-acid and kemptide

The teratogenic metabolite secalonic acid D deriving from the ergot-producing, rye-infecting ascomycete fungus Claviceps purpurea and from Penicillum oxalicum is an inhibitor of Ca2+- and phospholipid-dependent protein kinase C (PKC) and of the catalytic subunit of cyclic AMP-dependent protein kinase (cAK) (C50 values 15 microM and 12 microM, respectively). Secalonic acid D also inhibits Ca2+-calmodulin-dependent myosin light chain kinase (MLCK) and plant Ca2+-dependent protein kinase (CDPK). The inhibition of cAK by secalonic acid D is competitive with respect to both peptide substrate and ATP. However, secalonic acid D does not inhibit a high-affinity nucleotide-binding phosphatase from potato. A variety of other naturally-occurring teratogenic agents are not inhibitors of the protein kinases examined.

Topics: Amino Acid Sequence; Animals; Brain; Chickens; Claviceps; Cyclic AMP-Dependent Protein Kinases; Enzyme Inhibitors; Gizzard, Avian; Kinetics; Molecular Sequence Data; Mycotoxins; Myosin-Light-Chain Kinase; Oligopeptides; Penicillium; Peptide Fragments; Plants; Protein Kinase C; Protein Kinase Inhibitors; Rats; Teratogens; Xanthenes; Xanthones