Abstract
Raman spectroscopic measurements on aqueous solutions of poly(dG) · poly(dC)indicate that the conformation of the polynucleotides in this double helicalcomplex are distributed between the A and B types at room temperature, the Aform being predominant at −15°C and decreasing progressively upon raising thetemperature to 65°C. A reversible pretransition has been found in this complexnear 70°C. Modifications in the spectra at this temperature indicate no majorconformational changes, but rather suggest altered base pairing and hydration ofthe carbonyl groups, accompanied by a slight distortion of the double helix,resulting in a slightly reduced stacking of the cytosine bases. Measurements inself-pressurized solutions of the complex at high temperature show that it meltsat 103°C in 0.1M NaCl solution (107°C in 0.5M NaCl). These values are somewhatlower than those we have determined in the same manner for the complexpoly(dG-dC) · poly(dG-dC): 117°C in 0.1M MgCl2 and 113°C or higher in 0.1MNaCl solution.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
