TY - JOUR
T1 - The effect of cytochrome oxidase on lipid chain dynamics A nanosecond fluorescence depolarization study
AU - Kinosita, Kazuhiko
AU - Kawato, Suguru
AU - Ikegami, Akira
AU - Yoshida, Satoshi
AU - Orii, Yutaka
PY - 1981/9/21
Y1 - 1981/9/21
N2 - Molecular motions in membranes composed of purified cytochrome oxidase (EC 1.9.3.1) and synthetic lipid (l-α-dimyristoylphosphatidylcholine or l-α-dioleoylphosphatidylcholine) at various ratios were investigated with a lipophilic fluorescent probe 1,6-diphenyl-1,3,5-hexatriene. Nanosecond fluorescence depolarization kinetics of the probe showed that the rod-shaped probe molecules perform a fast wobbling motion (restricted rotation) in all membranes studied, presumably reflecting the motion of lipid acyl chains. At temperatures where the pure lipid was in the liquid-crystalline phase, presence of cytochrome oxidase reduced the angular range of the wobbling motion, whereas its rate; the wobbling diffusion constant, was unaffected. On the other hand, incorporation of the protein into lipid in the gel phase resulted in the increase in the wobbling diffusion constant while the range of the wobbling motion remained the same. A time-dependent view of lipid dynamics that accounts for the above findings, as well as the results of recent electron spin resonance and nuclear spin resonance studies of protein-lipid interactions, is proposed.
AB - Molecular motions in membranes composed of purified cytochrome oxidase (EC 1.9.3.1) and synthetic lipid (l-α-dimyristoylphosphatidylcholine or l-α-dioleoylphosphatidylcholine) at various ratios were investigated with a lipophilic fluorescent probe 1,6-diphenyl-1,3,5-hexatriene. Nanosecond fluorescence depolarization kinetics of the probe showed that the rod-shaped probe molecules perform a fast wobbling motion (restricted rotation) in all membranes studied, presumably reflecting the motion of lipid acyl chains. At temperatures where the pure lipid was in the liquid-crystalline phase, presence of cytochrome oxidase reduced the angular range of the wobbling motion, whereas its rate; the wobbling diffusion constant, was unaffected. On the other hand, incorporation of the protein into lipid in the gel phase resulted in the increase in the wobbling diffusion constant while the range of the wobbling motion remained the same. A time-dependent view of lipid dynamics that accounts for the above findings, as well as the results of recent electron spin resonance and nuclear spin resonance studies of protein-lipid interactions, is proposed.
KW - Boundary lipid
KW - Cytochrome oxidase
KW - Diphenyl hexatriene
KW - Fluorescence depolarization
KW - Lipid chain dynamics
KW - Wobbling motion
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U2 - 10.1016/0005-2736(81)90290-X
DO - 10.1016/0005-2736(81)90290-X
M3 - Article
C2 - 6271207
AN - SCOPUS:0019885982
VL - 647
SP - 7
EP - 17
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
SN - 0005-2736
IS - 1
ER -