亚相pH值对磷脂单层下甘氨酸结晶过程的影响

Effect of Subphase pH on Cystallization of Glycine Beneath Dipalmitoylphosphatidylcholine Langmuir Monolayer

以二棕榈酰磷脂酰胆碱(DPPC)有序单分子层为模板诱导亚相甘氨酸结晶的成核及生长。实验发现,在不同的pH条件下,甘氨酸结晶沿特定晶面取向生长,因而呈现不同的晶型。这种变化可归因于不同pH下甘氨酸分子所带电荷的性质和数量不同,使得甘氨酸分子以不同构型方式趋向于磷脂模板。该结果对于研究生物细胞膜中蛋白脂分子和核酸分子与氨基酸分子的相互作用有重要意义。

The oriented growth of glycine crystals beneath compressed Langmuir monolayers of dipalmitoylphosphatidylcholine（DPPC） was studied by means of electron probing microscopy （EPM）, scan electron micro-scopy（SEM） and X-ray diffractometry（XRD）. It was found that the morphology and the orientation of the formed crystals beneath the DPPC monolayer template changed with the pH of the glycine supersaturated solution. These changes are attributed to the glycine molecules with different charges and the mode of glycine molecules approaching the template at different pH values. These results are very important to the research of interactions between lipoprotein and amino acids or nucleic acids.