Imino form of cytosine
WitrynaIn fact, cytosine is the leading species (next to guanine) among nucleic acid bases in the number of tautomers. Depending on the environment, the existence of the amino-oxo, imino-oxo, and amino-hydroxy forms of cytosine has been predicted by both experimental and theoretical methods. Witryna1 wrz 2024 · Abstract. I-motif or C4 is a four-stranded DNA structure with a protonated cytosine:cytosine base pair (C+:C) found in cytosine-rich sequences.We have found that oligodeoxynucleotides containing adenine and cytosine repeats form a stable secondary structure at a physiological pH with magnesium ion, which is similar to i …
Imino form of cytosine
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WitrynaTautomerism of the cytosine molecule is discussed in connection with recent experimental matrix-isolation infrared spectroscopic measurements and recent ab … Witryna10 gru 2024 · The adenine–cytosine mismatch can form when adenine or cytosine exists in a rare imino form (denoted as A * and C *). This mismatch has experimentally and theoretically been investigated in several papers [1, 8,9,10,11,12].
WitrynaTautomerism of the cytosine molecule is discussed in connection with recent experimental matrix-isolation infrared spectroscopic measurements and recent ab initio calculations of relative stabilities of tautomers and of IR spectra for different tautomeric forms of the compound. Experimental IR spectra in the N-H and O-H stretching … Witryna22 wrz 2024 · The imino tautomers, in contrast, undergo a shift in the equilibrium between a closed and a more open, partially flipped state, towards the more open form upon complexation to the TDG enzyme. This stabilisation of the more open conformation is most pronounced for the non-cognate bases methyl-cytosine and hydroxyl …
WitrynaTautomeric Shifts II: amino and imino bases Standard amino and rare imino forms of C & A differ by a spontaneous proton shift (an H nucleus) between the the adjacent C and N molecules. The molecular … WitrynaFIG. 1: Tautomers of cytosine. In a) the keto form, in b) the enol form and in c) the imino form. The excited-state lifetime of cytosine in gas phase has been measured …
Witryna17 lip 2007 · The four bases of DNA can exist in at least two tautomeric forms as shown below. Adenine and cytosine (which are cyclic …
Witryna29 kwi 1993 · The imino tautomer of N4-hydroxy-cytosine in the anti rotameric form is by 12.8 kJ mol-1 less stable than the imino-syn form. The 5-fluoro substituent raises the energy difference between the syn and anti rotamers up to 38.5 kJ mol-1. ... The theoretical results also show that the amino tautomeric forms do not compete with the … binding posts stainlessWitrynaFor the IO tautomer, we also find a mechanism for the excited state interconversion of the cis and trans forms and for efficient radiationless decay through a conical intersection … binding post screws lowesWitrynabinding, base flip, bond cleavage) and with the base in amino or imino form, though the amino form dominates in unbound DNA [6,27,28]. It has also been suggested that the higher oxidised forms of methyl-cytosine—FC and CAC—could be recognised because of their higher propensity, compared to HMC and MC, to form imino tautomers [4,7]. binding post screwsWitrynaWe have measured the IR and UV spectra of cytosine in a low-temperature argon matrix.An attempt was made to determine the tautomeric ratios existing in the matrix, making use of the matrix-isolation IR spectrum and computed IR intensities of the tautomers in a least squares fitting procedure. The mole fractions are about 0.22 for … binding post for speakersWitryna16 cze 2008 · The subject of the present study is tautomerization specifically in cytosine. It is now generally accepted that cytosine has three primary, low-energy forms as … binding post connectors subwoofer boxWitryna8 paź 2015 · The calculations, in gas phase and in water, are performed at B3LYP/6-311++G(d,p) level. In gas phase, it is observed that any tautomeric form of investigated mismatches is more stabilized when adenine is protonated. As for the neutral mismatches, the mismatches containing amino form of cytosine and imino form of … binding post screws stainlessWitrynaeffect would be expected for the 3H-imino forms of cyto ... between guanine and the amino form of cytosine. University Chemical Laboratory, Cambridge. Received August 12, 1968. binding post screw