Protein tracking and detection of protein motion using atomic force microscopy

Height fluctuations over three different proteins, immunoglobulin G, urease, and microtubules, have been measured using an atomic force microscope (AFM) operating in fluid tapping mode. This was achieved by using a protein-tracking system, where the AFM tip was periodically repositioned above a sing...

Full description

Saved in:
Bibliographic Details
Published inBiophysical journal Vol. 70; no. 5; pp. 2421 - 2431
Main Authors Thomson, N.H., Fritz, M., Radmacher, M., Cleveland, J.P., Schmidt, C.F., Hansma, P.K.
Format Journal Article
LanguageEnglish
Published United States Elsevier Inc 01.05.1996
Subjects
Animals
Brain - ultrastructure
Cattle
Fourier Analysis
Freeze Drying
Immunoglobulin G - physiology
Immunoglobulin G - ultrastructure
Microscopy, Atomic Force - instrumentation
Microscopy, Atomic Force - methods
Microtubules - physiology
Microtubules - ultrastructure
Quaternary Ammonium Compounds
Surface-Active Agents
Time Factors
Urease - physiology
Urease - ultrastructure
Online AccessGet full text

Cover

More Information
Summary:Height fluctuations over three different proteins, immunoglobulin G, urease, and microtubules, have been measured using an atomic force microscope (AFM) operating in fluid tapping mode. This was achieved by using a protein-tracking system, where the AFM tip was periodically repositioned above a single protein molecule (or structure) as thermal drifting occurred. Height (z-piezo signal) data were taken in 1 - or 2-s time slices with the tip over the molecule and compared to data taken on the support. The measured fluctuations were consistently higher when the tip was positioned over the protein, as opposed to the support the protein was adsorbed on. Similar measurements over patches of an amphiphile, where the noise was identical to that on the support, suggest that the noise increase is due to some intrinsic property of proteins and is not a result of different tip-sample interactions over soft samples. The orientation of the adsorbed proteins in these preliminary studies was not known; thus it was not possible to make correlations between the observed motion and specific protein structure or protein function beyond noting that the observed height fluctuations were greater for an antibody (anti-bovine IgG) and an enzyme (urease) than for microtubules.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0006-3495
1542-0086
DOI:10.1016/S0006-3495(96)79812-0