Proflavine nucleic acid chemical

Nucleic Acid Base Resonances The chemical shifts of the nonexchangeable protons in poly(dA-dT), the Nuc/D = 24 complex and the Nuc/D = 8 complex in 1 M NaCl solution are plotted as a function of temperature in Figure 19. The nucleic acid nonexchangeable proton chemical shifts in the duplex state are either unperturbed (adenosine H-8, H-2, and thymidine CH3-5) or shift slightly upfield (thymidine H-6) on complex formation (Figure 19). By contrast, the thymidine H-3 exchangeable proton located in the center of the duplex resonates 0.35 ppm to higher field in the Nuc/D = 8 proflavine complex compared to its position in the... 

Figure 19. The temperature dependence of the nucleic acid (O) and proflavine (0) chemical shifts between 5.5 and 8.6 ppm for poly(dA-dT) and the Nuc/D = 24 and 8 proflavine poly(dA-dT) complexes in /M NaCl, lOmWl cacodylate, lOmM EDTA, 2 HO between 50° and 100°C. The poly(dA-dT) concentration was fixed at I2.6mM in phosphates and the proflavine concentration was varied to make the different Nuc/D ratio complexes.

Macromolecules may or may not fluoresce. Those that do are considered to contain intrinsic fluors. The common intrinsic fluors for proteins are tryptophan, tyrosine, and phenylalanine (the same three groups that absorb UV radiation). Macromolecules that have no intrinsic fluors can be made fluorescent by adding an extrinsic fluor to them. This is done by the process of chemical coupling or sample binding. The most common extrinsic fluors for proteins are l-aniline-8-naphthalene sulfonate, l-dimethylaminonaphthalene-5-sulfonate, dansyl chloride, 2-p-toluidyl-naphthalene-6-sulfonate, rhodamine, and fluorescein. The most common extrinsic fluor for nucleic acids are various acridienes (acridine orange, proflavin, acriflavin) and ethidium bromide. 

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