[Dual center binding of cocarcinogens of the phorbol series with a receptor]

A systemic study based on literature data concerning the structure-activity relationships within a set of phorbol derivatives was carried out. Evidence in favour of the existence of two binding sites for phorbol derivatives on the receptor surface was obtained. The diterpenoid cycle binding site and the hydrophobic site for the binding of acyl hydrocarbon chains 12 and 13 were identified. The tumour-promoting effects of phorbol esters are due to their capability to simultaneously interact with the both sites of the receptor.