Fractal-like patterns in DNA films, B form at 0% relative humidity, and antiheteronomous DNA: An ir study
✍ Scribed by B. Sclavi; W. L. Peticolas; J. W. Powell
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1994
- Tongue
- English
- Weight
- 937 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
This report details the observation of ( a ) the intact double helix of DNA at 0% relative humidity in poly(dA) -poly(dT) and poly(dA-dT) -poly(dA-dT) films, ( b ) the fractallike growth of DNA crystals in films of poly ( dA)poly ( d T ) , and ( c ) poly (dA) * poly ( d T )
with adenines in the B form and thymines in the A form. Observation ( a ) is based on the behavior of the middle ir signature of double-helical base stacking, the 1714 cm-' peak, at low water activity. This observation is modeled as a trapping of water in the polycrystalline part of these films. We interpret the glyrosidic region of the middle ir spectra of the polycrystalline films of poly( dA) *poly(dT) at 0% relative humidity to indicate that at least part of the adenine strand in is the B conformation and the thymine strand is in the A form, whereas previous assignments of poly (dA) * poly( d T ) films at 75% relative humidity indicated the opposite strand conformation assignment [ E.