用AFM研究杜仲抗真菌蛋白的晶体生长

随着后基因组时代的到来以及蛋白质组学研究的深入开展,研究蛋白质晶体生长成为生物化学和结构生物学领域一个广泛关注的课题.通过使用原子力显微镜(Atomic Force Microscope,简称AFM)对杜仲抗真菌蛋白(eucommia antifungal protein,简称EAFP)的晶体在有母液存在下原位实时动态地进行了晶面生长观察.研究结果表明:不同过饱和度对EAFP晶体生长形貌的影响较大,较高的过饱和度下生长很快,生长台阶密度高,较高的过饱和度下主要进行各向异性二维台阶的发生、发展,较低的过饱和度下主要采用螺旋位错的生长方式,当过饱和度极低时生长缓慢,且晶体表面有很多小孔存在,晶面生长很不完整;还对不同过饱和度下晶体生长速率进行了定量的测量,也反映了过饱和度对EAFP晶体生长的影响;同时对在AFM观察过程中由探针的扫描速度和方向对表面形貌的影响进行了讨论.

The Growth of EAFP Crystal by In Situ Atomic Force Mircroscopy

The dynamic changes of morphology on the { 100} face of EAFP(eucommia antifungal protein) crystals were examined by in situ Atomic Force Microscopy (AFM) in their mother liquor. According to the AFM results different supersaturations are responsible for these morphological changes. At hight supersaturations the EAFP crystals grow very fast and the density of growth steps is very high. At higher supersaturations the formation and development of 2 - D step dominate the growth of EAFP surface. At lower supersaturations the anisotropic spiral dislocations are major growth on the EAFP crystal surface. At very low supersaturations the EAFP crystals grow very slow and there are many holes in the surface which indicate the incomplete growth of the surface. Meanwhile the effects of scanning rate and scanning direction are studied here.