Interaction be tween different cations with tautomer ic forms of thiocytosine

The m etal ions are involved in almost all biologic al processes, such as the regulation of enzym e, stabilizat ion and fun ction of nucleic acids. Therefore further investigations on how metal cations interact with biological mo lecules and how these interactions affect or c ontrol the f unctions of biological molecules are essential. The st udy of the tautomerism of nucleo bases is important due to the effects on base p airing, base stacking an d formation of H-bonded complexes [۱]. Thio cytosine is an analog of the natura l nucleic a cid base cytosine whose oxygen atom is substituted by sulfur atom.Thiocytosine has beenfound in tRNAmolecules i n Escherich ia coli[۲]. Tautomerism of thiocytosine has be en studied as that of cytosine [۳].I n this work we inv estigated in teraction between tautomer form s of thiocytosine with metal cations Ca+۲ and Mg+۲. The aim of the present w ork is to find the influence of metal cations on the structural and energetic properties of different tautomers of thiocytosine.

کلیدواژه ها:

Thiocytosine ، Tau tomerization ، Cation-he teroatom ، Bidentate