CAJ | 학술논문

应用同步辐射X射线衍射和差示扫描量热法研究了由不同结构的固醇(胆同醇、脱氖胆固醇、豆同醇、谷固醇、麦角同醇以及固醇核)和二棕榈酰磷脂酰胆碱(DPPC)二元体系形成的液态有序相.研究表明,胆固醇比植物同醇(豆固醇和谷同醇)和真菌固醇(麦角固醇)能更有效地与DPPC形成液态有序相(Lo);有胆同醇或者脱氢胆固醇参与的液态有序相能够在较宽的温度范围内保持稳定,而由植物固醇和真菌同醇参与的液态有序相对温度有较强的依赖性,在DPPC主相变温度附近有明显的热致相变过程,因此这一液态有序相应该进一步区分为Loβ和Loα相.研究结果有助于阐明同醇尾链在液态有序相以及脂筏中的作用,也有助于理解在进化过程中动物细胞膜为何选择胆固醇作为主要固醇.
응용동보복사X사선연사화차시소묘량열법연구료유불동결구적고순(담동순、탈내담고순、두동순、곡고순、맥각동순이급고순핵)화이종려선린지선담감(DPPC)이원체계형성적액태유서상.연구표명,담고순비식물동순(두고순화곡동순)화진균고순(맥각고순)능경유효지여DPPC형성액태유서상(Lo);유담동순혹자탈경담고순삼여적액태유서상능구재교관적온도범위내보지은정,이유식물고순화진균동순삼여적액태유서상대온도유교강적의뢰성,재DPPC주상변온도부근유명현적열치상변과정,인차저일액태유서상응해진일보구분위Loβ화Loα상.연구결과유조우천명동순미련재액태유서상이급지벌중적작용,야유조우리해재진화과정중동물세포막위하선택담고순작위주요고순.
The effect of cholesterol,desmosterol,stigrnasterol,sitosterol,ergosterol,and androsterol on the phase behavior of aqueous dispersions of dipalmitoylphosphatidylcholine(DPPC) was studied to understand the role of the side chain in the formation of ordered phases of the type observed in membrane rafts.Thermotropic changes in the structure of mixed dispersions and transition enthalpies were examined by synchrotron X-ray diffraction(XRD) and differential scanning calorimetry(DSC).The observations indicated that cholesterol was more efficient than phytosterols (stigmasterol and sitosterol)or ergosterol in its interaction with DPPC to form the liquid ordered phase(Lo).The Loreduced by cholesterol or desmosterol was stable over a wide temperature range,whereas,the liquid ordered phase contaimng phytostemls or ergosterol was profoundly dependent on temperature,which should be distinguished as Loβ and Loα,representing the phases below and above the main transition temperature.The characteristies in forming ordered structures of cholesterol and other sterols imply that the evolution may have selected cholesterol as the most efficient sterol for animals to form rafts in their cell membranes.