Biomolecular Imaging with the Atomic Force Microscope

High resolution surface structure of E. coli GroES oligomer by atomic force microscopy

“…Because of the variable conformations observed by EM, it was even suggested that GroES could have a flexible structure or a symmetry other than the seven-fold [18]. Since the atomic force microscopy (AFM) has been shown to be capable of obtaining high resolution surface structures of several oligomeric bacterial proteins (for recent reviews, see [24][25][26]), we have applied this method to determine the surface structure of GroES under aqueous solutions. We show that the subunit structure can be clearly resolved in the AFM images without image processing/averaging.…”

An atomic force microscopy investigation of cyanophage structure

“…Hydrated samples were scanned at 25 • C using oxidesharpened silicon nitride tips in a 75 l fluid cell containing buffer. In all cases images were collected in tapping mode (Hansma and Hoh, 1994;Hansma and Pietrasanta, 1998) with an oscillation frequency of 9.2 kHz in fluid and 300 kHz in air, with a scan frequency of 1 Hz.…”

Nanotechnologies in proteomics

“…At the same time, these two technologies present interest from the viewpoint of high spatial resolving capacity of biological molecules -in the order of 1 nm and less. The appearance, in recent years, of increasingly numerous studies dealing with the analysis of single molecules and based on the tunnelling and, especially, on the AFM techniques [109][110][111][112][113][114][115][116][117][118][119][120][121][122][123] is explainable. Indeed, the AFM offers a unique ability to easily detect and visualize proteins and their complexes in nearnative conditions while not requiring protein labelling (in contrast to the earlier mentioned optical microscopy techniques) [114].…”

“…Among these techniques are the STM and the AFM of biomolecules. The STM and AFM may be classed with the 'scanning near-field microscopy' approach, and both are finding an increasing application in structural studies of biological systems with high nanometric or subnanometric resolution (such as proteins and their complexes, nucleic acids, biomembranes and cells) [110,111] in near-native conditions. The principle of operation of the two techniques is the same: the probe tip of the device scans the area of the decay length of some nearly located field across the sample surface.…”

“…These changes reflect the macromolecule topography. Such an approach enables to improve the quality of molecules' images [111]. With native proteins, the method ensures the vertical resolution of ,0.1 nm and the lateral resolution of up to 0.5 nm [112,113].…”