title: Bromine residue at hydrophilic region influences biological activity of aplysiatoxin, a tumor promoter.
abstract: Aplysiatoxin and debromoaplysiatoxin, which are isolated from the seaweed, Lyngbya gracilis, differ in their chemical structure only by the presence or absence of a bromine residue in the hydrophilic region. The function and the structure-activity relation of the hydrophilic region are not known. Aplysiatoxin increased malignant transformation, stimulated DNA synthesis, and inhibited the binding of phorbol-12,13-dibutyrate and epidermal growth factor to cell receptors. Debromoaplysiatoxin inhibited the binding of these two substances as strongly as aplysiatoxin but did not increase malignant transformation or stimulate DNA synthesis. These results indicate that a slight change in the chemical structure of the hydrophilic region of aplysiatoxin affects its abilities to increase cell transformation and stimulate DNA synthesis and that the abilities of the tumor promoters to inhibit the binding of phorbol-12,13-dibutyrate and epidermal growth factor are dissociable from their abilities to increase cell transformation and stimulate DNA synthesis under some circumstances.
mesh_terms: D000818:Animals; D029742:Caenorhabditis elegans Proteins; D002273:Carcinogens / Q000494:pharmacology*; D002352:Carrier Proteins; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D055598:Chemical Phenomena; D002621:Chemistry; D004247:DNA / Q000096:biosynthesis; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors; D007783:Lactones / Q000032:analysis / Q000494:pharmacology*; D008235:Lyngbya Toxins; D051379:Mice; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000378:metabolism; D011493:Protein Kinase C; D011956:Receptors, Cell Surface / Q000378:metabolism; D011955:Receptors, Drug; D013329:Structure-Activity Relationship
chemical_list: D029742:Caenorhabditis elegans Proteins; D002273:Carcinogens; D002352:Carrier Proteins; D007783:Lactones; D008235:Lyngbya Toxins; D010703:Phorbol Esters; D011956:Receptors, Cell Surface; D011955:Receptors, Drug; C083141:phorbol ester binding protein; C027776:phorbol ester receptor; D015240:Phorbol 12,13-Dibutyrate; C017179:debromoaplysiatoxin; C006610:aplysiatoxin; D004815:Epidermal Growth Factor; D004247:DNA; D066246:ErbB Receptors; D011493:Protein Kinase C