Here we review studies that provided important information about conformational properties of DNA using circular dichroic (CD) spectroscopy. The conformational properties include the B-family of structures, A-form, Z-form, guanine quadruplexes, cytosine quadruplexes, triplexes and other less characterized structures. CD spectroscopy is extremely sensitive and relatively inexpensive. This fast and simple method can be used at low- as well as high-DNA concentrations and with short- as well as long-DNA molecules. The samples can easily be titrated with various agents to cause conformational isomerizations of DNA. The course of detected CD spectral changes makes possible to distinguish between gradual changes within a single DNA conformation and cooperative isomerizations between discrete structural states. It enables measuring kinetics of the appearance of particular conformers and determination of their thermodynamic parameters. In careful hands, CD spectroscopy is a valuable tool for mapping conformational properties of particular DNA molecules. Due to its numerous advantages, CD spectroscopy significantly participated in all basic conformational findings on DNA.

• MeSH
• A-DNA chemie   MeSH
• cirkulární dichroismus * MeSH
• denaturace nukleových kyselin MeSH
• DNA chemie   MeSH
• G-kvadruplexy MeSH
• konformace nukleové kyseliny MeSH
• Z-DNA chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• A-DNA MeSH
• DNA MeSH
• triplex DNA MeSH Prohlížeč
• Z-DNA MeSH

It is shown, using circular dichroism spectroscopy, that poly(dI-dC) is capable to isomerize into both Z-DNA and A-DNA in concentrated NaCl + NiCl2 and trifluoroethanol solutions, respectively. This polynucleotide also undergoes a cooperative, two-state transition in ethanol into a structure which most probably is a canonical B-DNA. This implies that the conformation of poly(dI-dC) is unusual in low-salt aqueous solution. The canonical B-DNA is also adopted by poly(dI-methyl5dC) in trifluoroethanol while this polynucleotide adopts Z-DNA not only in NaCl + NiCl2 but also in the presence of MgCl2. Poly(dI-methyl5dC) partially adopts X-DNA in concentrated CsF and mainly ethanolic solutions. Poly(dI-bromo5dC) isomerizes into Z-DNA not only in concentrated NaCl even in the absence of NiCl2 but also in concentrated MgCl2. This polynucleotide transforms between two distinct variants of Z-DNA in ethanol or trifluoroethanol solutions.

• MeSH
• chlorid hořečnatý MeSH
• chlorid sodný MeSH
• cirkulární dichroismus MeSH
• DNA chemie   MeSH
• isomerie MeSH
• konformace nukleové kyseliny MeSH
• polydeoxyribonukleotidy chemie   MeSH
• roztoky MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chlorid hořečnatý MeSH
• chlorid sodný MeSH
• DNA MeSH
• poly d(I-C) MeSH Prohlížeč
• polydeoxyinosinic-polydeoxy-(5-bromocytidylic)acid MeSH Prohlížeč
• polydeoxyinosinic-polydeoxy-(5-methylcytidylic)acid MeSH Prohlížeč
• polydeoxyribonukleotidy MeSH
• roztoky MeSH