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1022564 
Technical Report 
Structure and activity of a natural phytotoxin, tentoxin. New insights in enzymatic mechanism of chloroplast H+ ATP-synthase 
Andre, F; Pinet, E 
1997 
BIOSIS/97/24888 
191 
3 
401-432 
French 
BIOSIS COPYRIGHT: BIOL ABS. A mini review of the properties of the natural phytotoxin, tentoxin, is proposed. In particular, the biological activities of tentoxin on the chloroplast F0F1 proton ATPase, which realizes the synthesis of ATP at the expense of an electrochemical gradient of protons, are discussed. In this respect, structure-activity relationships of tentoxin have been re-examined in the light of the recent developments obtained by two-dimensional proton nuclear magnetic resonance (81). The conformations of the cyclic tetrapeptide (cyclo-(L-MeAla1-L-Leu2-MePhe((Z)DELTA)3-Gly4)) have been studied in aqueous solution at various temperatures. Contrary to what was observed in early studies in chloroform, tentoxin was proved to exhibit multiple exchanging conformations in water. Four conformations with different proportions (51, 37, 8 and 4%) were found. Models were derived from nuclear magnetic resonance parameters and restrained molecular dynamics simulations. They confirmed that the four 
Biochemical Studies-General; Enzymes-General and Comparative Studies; Toxicology-General; Plant Physiology