Dynamics of the B-to-Z transition in supercoiled DNA
| Autor: | Fritz M. Pohl |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
DNA
Bacterial Multidisciplinary Transition (genetics) DNA Superhelical Stereochemistry Kinetics Antibodies Monoclonal Chloroquine Sequence (biology) DNA Sodium Chloride chemistry.chemical_compound Plasmid Reaction rate constant chemistry Antibody Specificity Multiple cloning site Biophysics Nucleic Acid Conformation DNA supercoil Plasmids Research Article |
| Zdroj: | Proceedings of the National Academy of Sciences. 83:4983-4987 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.83.14.4983 |
| Popis: | The sequence (dC-dG)16, inserted into the polylinker of plasmid pUC8, adopts a left-handed Z-DNA conformation at "natural" supercoil density. The radioactively labeled monoclonal antibody Z-D11, which has a very high affinity for this DNA conformation, provides a convenient sensitive tool to measure selectively the amount of Z-DNA. Chloroquine reversibly changes the supercoil density of plasmid DNA and thereby the equilibrium between right- and left-handed double-helical DNA. The time-dependent formation or disappearance of Z-DNA was measured by using the antibody either as a fast indicator of Z-DNA or as an additional effector of the B-to-Z equilibrium. In the middle of the transition, a relaxation time of about 1 hr is observed in 0.1 M NaCl at 22 degrees C. The kinetic data are compatible with an all-or-none transition between the two conformations. The overall rate constant for Z-DNA formation, kBZ, decreases with the square of the chloroquine concentration, while the reverse one, kZB, increases with about the fourth power. |
| Databáze: | OpenAIRE |
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