Atomic force microscopic observation of surface structure of purified protein molecules in vitro
- VernacularTitle:原子力显微镜观察体外纯化蛋白分子的表面结构
- Author:
Zhao-ying CHEN
1
;
Xiao-feng FANG
;
Dan-yan LIU
;
Meng-qin CHEN
;
Xi LING
;
Jie-min ZHAO
;
Wei WEI
;
Yu-jing WU
Author Information
- Publication Type:Journal Article
- Keywords: atomic force microscopy; scanning electron micro-scope; receptor structure; protein structures in vitro; ultrastruc-ture; mica carrier
- From: Chinese Pharmacological Bulletin 2025;41(1):193-199
- CountryChina
- Language:Chinese
- Abstract: Aim To compare the observation results of atomic force microscopy(AFM)and scanning electron microscopy(SEM),and to summarize the main problems and solutions of AFM in observing biological macromolecules,using the observa-tion subjects of protein samples purified by our research group.Methods The protein samples were diluted to 15 nmol·L-1 with PBS,fixed on glass slides,silicon wafers,and mica sheets,dried,and made into solid-phase observation samples.SEM sam-ples were plated with platinum before observation.The surface structures of proteins were observed using AFM and SEM,sample heights were calculated,and differences in results were com-pared.Results Protein samples with positive charges tended to shift to the right during observation due to the repulsion of the AFM probe;mica sheets could effectively eliminate the positive charge of proteins to avoid sample movement;PBS provided a stable environment for protein samples,but the crystallization of PBS salts interfered with probe operation and imaging clarity;SEM samples needed to be plated with platinum before observa-tion and could not achieve the precision of AFM.Conclusions Both AFM and SEM can directly observe protein structures in vitro,with AFM providing higher precision results;when protein sample stability permits,ultrapure water is preferred as the sol-vent carrier,and volatile liquids such as ethanol can also serve as solvent carriers.The application of AFM offers a new approach for pharmacological studies on interactions between biological macromolecules.
