Transverse motion of chlorophyll derivatives in phospholipid bilayers.
Chlorophyll derivatives were synthesized with spin labels attached to the porphyrin ring. These labels were incorporated into egg phosphatidylcholine vesicles in order to estimate the transbilayer motion (flip-flop) of this class of photosynthetic pigments. Using the ascorbate reduction method, the upper limit to the spin label half-life is tau 1/2 approximately 4 min at 0 degrees C. The flip-flop rate is rapid compared to that of a phospholipid spin label under the same conditions. The presence or absence of magnesium in the center of the porphyrin ring had no measurable effect on the flip-flop rate.
D055598:Chemical Phenomena; D002621:Chemistry; D002734:Chlorophyll; D004578:Electron Spin Resonance Spectroscopy; D008051:Lipid Bilayers; D010743:Phospholipids; D013113:Spin Labels
D008051:Lipid Bilayers; D010743:Phospholipids; D013113:Spin Labels; D002734:Chlorophyll