کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1945651 | 1053270 | 2007 | 6 صفحه PDF | دانلود رایگان |
Clostridium perfringens alpha-toxin degrades phosphatidylcholine (PC) in the bilayer of liposomes and destroys the membrane. The effect of the type and position of unsaturation in the fatty acyl chain of PC (18:0/18:1 PC) synthesized on the toxin-induced leakage of carboxyfluorescein (CF) from PC liposomes was examined. Differential scanning calorimetry showed that the phase transition temperature (Tm) was minimal when the triple bond was positioned at C (9) in the sn-2 acyl chain. The toxin-induced CF leakage decreased with the migration of the bond from C (9) to either end of the acyl chain in PC. The PC containing the cis-double bond had a similar Tm to that with the triple bond, but a lower value than the PC containing the trans-double bond. Furthermore, the toxin-induced leakage from liposomes composed of PC containing the cis-double bond resembled that with PC having the triple bond and was greater than that from liposomes with PC having the trans-double bond. The binding of a H148G mutant to PC liposomes showed a reciprocal relationship in terms of the Tm value of PC containing the triple bond. These results indicate that the toxin-induced membrane damage is closely related to membrane fluidity in liposomes.
Journal: Biochimica et Biophysica Acta (BBA) - Biomembranes - Volume 1768, Issue 11, November 2007, Pages 2940–2945