Early melting of supercoiled DNA

Yu L. Lyubchenko, L. S. Shlyakhtenko

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


Denaturing gradient gel electrophoresis (formamide with urea) has been used to study the melting of supercoiled DNA. A linegr gradient of denaturant concentration proportional to a 25°C linear increase of temperature (Teff) from the left to the righ edge of the gel was created perpendicular to DNA migration. The mobility of supercoiled DMA molecules was shown to drop to the level of relaxed molecules a long way (5-30°C) before linear DNA began to melt. The futher increase of Teff, including the roelting range for linear molecules, caused no appreciable changes in the mobility of relaxed molecules. The transition curves are S-shaped for all the topoisoraers, and an increase of superhelicity shifts the transition towards lower Teff values. The analysis of the results indicates that the observed relaxation of superhelical molecules is due to denatured region forming in them, their size increasing with the topoisomer number.

Original languageEnglish (US)
Pages (from-to)3269-3281
Number of pages13
JournalNucleic acids research
Issue number8
StatePublished - Apr 25 1988
Externally publishedYes

ASJC Scopus subject areas

  • Genetics


Dive into the research topics of 'Early melting of supercoiled DNA'. Together they form a unique fingerprint.

Cite this