Abstract
A novel inhibitor of protein kinase C was found in the fermentation of a soil actinomycete, strain RK-1409. According to the taxonomic studies, the producing strain was designated as Streptomyces platensis subsp. malvinus RK-1409. The protein kinase C inhibitor, RK-1409 (7-oxostaurosporine) inhibited the morphological change of a human chronic erythroleukemia cell, K-562, induced by phorbol 12, 13-dibutyrate (PDBu) at the concentration of 10ng/ml. The concentration of 3ng/ml inhibited the activity of protein kinase C in vitro. RK-1409 inhibited the cell cycle progression at G2 phase of K-562 cells.
