The C4 hydroxyl group of phorbol esters is not necessary for protein kinase C binding.

M Tanaka, K Irie, Y Nakagawa, Y Nakamura, H Ohigashi, P A Wender

Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan.

Bioorganic & medicinal chemistry letters 2001 Mar 12

filter terms:

To investigate the role of the hydroxyl group at position 4 of the phorbol esters in protein kinase C (PKC) binding and function, 4beta-deoxy-phorbol-12,13-dibutyrate (4beta-deoxy-PDBu, 5a) and 4beta-deoxy-phorbol-13-acetate (6a) were synthesized from phorbol (1). The binding affinities of these 4beta-deoxy compounds (5a, 6a) to the 13 PKC isozyme C1 domains were quite similar to those of the corresponding 4beta-hydroxy compounds (4a, 4b), suggesting that the C4 hydroxyl group of phorbol esters is not necessary for PKC binding. Moreover, functional assays showed that 4beta-deoxy-PDBu (5a) exhibited biological activities (Epstein-Barr virus induction and superoxide generation) equally potent to those of PDBu (4a). These solution phase results differ from expectations based on the previously reported solid-phase structure of the complex of PKCdelta-C1B and phorbol-13-acetate (4b).

Citation

M Tanaka, K Irie, Y Nakagawa, Y Nakamura, H Ohigashi, P A Wender. The C4 hydroxyl group of phorbol esters is not necessary for protein kinase C binding. Bioorganic & medicinal chemistry letters. 2001 Mar 12;11(5):719-22