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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(胆固醇、脱氢胆固醇、豆固醇、谷固醇、麦角固醇以及固醇核)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,胆固醇比植物固醇(豆固醇和谷固醇)和真菌固醇(麦角固醇)能更有效地与DPPC形成液态有序相(Lo);有胆固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固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固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.
The effects of different structures of sterols (cholesterol, dehydrocholesterol, sterol, sitosterol, ergosterol and sterol nuclei) and dipalmitoylphosphatidylcholine were studied by using synchrotron radiation X-ray diffraction and differential scanning calorimetry Choline (DPPC) binary system.Studies have shown that cholesterol can form liquid state more efficiently with DPPC than phytosterols (steryl and sitosterol) and fungosterol (ergosterol) Phase (Lo). The liquid ordered phase with cholesterol or dehydrocholesterol can stay stable over a wide temperature range, whereas the liquid ordered relative temperature by phytosterols and mycotoxins has a strong dependence, In the DPPC near the main phase transition temperature obvious thermal induced phase transition, so the liquid order should be further divided into Loβ and Loα phase.The results help to elucidate the steric hindgut in liquid phase and lipid raft Also helps to understand why animal membranes select cholesterol as the major steroid during evolution.