Probing specific molecular conformations with the scanning force microscope. Complexes of plasmid DNA and anti-Z-DNA antibodies
Open Access
- 1 January 1994
- journal article
- Published by Oxford University Press (OUP) in Nucleic Acids Research
- Vol. 22 (16), 3288-3292
- https://doi.org/10.1093/nar/22.16.3288
Abstract
An anti-Z-DNA IgG antibody was used to probe for the left-handed Z-DNA conformation of a d(CG)11 insert in a negatively supercoiled plasmid DNA (pAN022). The complexes were spread on mica in the presence of quaternary ammonium detergent benzyldimethylalkylammonium chloride and imaged with a scanning force microscope (SFM). The high affinity anti-Z-DNA antibody was retained even after restriction endonuclease cleavage of the DNA. The two arms in the product molecules had unequal lengths in conformity with the known location of the Z-DNA forming insert. Most complexes exhibited one IgG per DNA molecule. The bound antibodies were up to ˜ 3 5 nm in diameter and extended approximately 2 nm from the mica surface. They were generally in a lateral orientation relative to the DNA, in accordance with prior chemical modification experimental data indicating a bipedal mode of binding for an anti-Z-DNA IgG. However, the SFM images also suggest that the DNA bends to accommodate the two Fab combining regions of the antibody. This study demonstrates the utility of the SFM for investigating conformation-dependent molecular recognition.Keywords
This publication has 28 references indexed in Scilit:
- Atomic force microscopy of oriented linear DNA molecules labeled with 5nm gold spheresNucleic Acids Research, 1993
- Substrate preparation for reliable imaging of DNA molecules with the scanning force microscopeUltramicroscopy, 1992
- Circular DNA molecules imaged in air by scanning force microscopyBiochemistry, 1992
- Interactions ofDrosophillaDNA topoisomerase II with left-handed Z-DNA in supercoiled minicirclesNucleic Acids Research, 1991
- Z DNA and loop structures by immunoelectronmicroscopy of supercoiled pRW751, a plasmid containing left-handed helicesNucleic Acids Research, 1988
- Atomic Force MicroscopePhysical Review Letters, 1986
- Left-handed DNA: from Synthetic Polymers to ChromosomesJournal of Biomolecular Structure and Dynamics, 1983
- Crystallographic refinement and atomic models of the intact immunoglobulin molecule Kol and its antigen-binding fragment at 3.0 Å and 1.9 Å resolutionJournal of Molecular Biology, 1980
- EPORNITICS OF ASPERGILLOSIS IN MALLARDS (Anas platyrhynchos) IN NORTH CENTRAL COLORADOJournal of Wildlife Diseases, 1978
- Three-dimensional structure of an intact human immunoglobulin.Proceedings of the National Academy of Sciences, 1977