Compression elasticity of glucagon amyloid fibrils in the transverse direction was investigated by a nanoindentation approach based on atomic force microscopy (AFM).With force-volume mapping, we obtained the correlations between radially applied force and compression of amyloid fibrils, from which the radial compressive elasticity can be deduced.The estimated elastic modulus at three typical locations of fibrils varied from (0.72±0.80) GPa to (1.26±0.62) GPa under small external forces, imply-ing the structural heterogeneity of different fibrils.
ZHOU XingFei CUI ChengYi ZHANG JinHai LIU JianHua LIU JingSong
利用原子力显微镜(Atomic Force Microscopy,AFM)观察了不同温度下胰高血糖素纤维的生长过程,发现在较低温度下(20℃)主要生成粗短的具有螺旋状结构的纤维;在较高温度下(50℃)以细长的非螺旋状纤维为主;而在中间温度下(35℃)这两种类型的纤维数量差不多。统计结果表明,细长的非螺旋状纤维的生长速度比粗短的快很多,说明这两种类型的纤维具有不同结构。同时我们发现,变换生长温度,两种类型的纤维一旦形成能够比较稳定的存在。
The mechanical property of individual ferritin was measured with force-volume mapping (FV) under contact mode of atomic force microscopy (AFM) in this work. The elastic modulus of individual ferritin was estimated by the Hertz mode. The estimated value of the elastic modulus of individual ferritin was about 250-800 MPa under a small deformation. In addition, the elastic modulus of individual ferritin was compared with that of the colloid gold nanoparticle.
