Poly(pyrimidine) . poly(purine) tracts have been discovered in the 5'-flanking regions of many eucaryotic genes. They may be involved in the regulation of expression since they can be mapped to the nuclease-sensitive sites of active chromatin. We have found that poly(pyrimidine) . poly(purine) DNAs which contain 5-methylcytosine (e.g. poly[d(Tm5C)] . poly[d(GA)]) will form a triplex at a pH bel...

objective: to determine the association between serum 25 - hydroxy vitamin d concentration and anthropometric indices in patients with polycystic ovarian syndrome (pcos). materials and methods: this is a descriptive cross - sectional study which was carried out on women with pcos aged 19-39 years old referred to an infertility clinic of alzahra hospital, rasht, iran during september2011- march2...

The conformational change for the alternating purine-pyrimidine polydeoxyribonucleotides i.e. poly d(A-T), poly d(G-C), and poly d(A-C) poly d(G-T) from a right-handed conformation at room temperature to the left-handed Z-DNA like double helix at elevated temperatures has been studied by UV spectroscopy, Raman spectroscopy, and by adiabatic differential scanning microcalorimetry (DSC) in the pr...

Typical CD spectrum of the right-handed poly[d(A-T)2] was reversed when trans-bis(N-methylpyrimidium-4-yl)diphenyl porphyrin (trans-BMPyP) was bound, suggesting that the helicity of the polynucleotide was reversed to the left-handed form. The formation of the left-handed Z-form poly[d(A-T)2] was confirmed by (31)P NMR, in which a single (31)P peak of B-form poly[d(A-T)2] was split into two peak...

Parazoanthoxanthin A is a fluorescent yellow nitrogenous pigment of the group of zoanthoxanthins, which show a broad range of biological activity. These include, among others, the ability to bind to DNA. In this study we have used a variety of spectroscopic (intrinsic fluorescence emission and UV-spectroscopy) and hydrodynamic techniques (viscometry) to characterize in more detail the binding o...

Introduction Recently a structure was proposed for poly d(GC). poly d(GC) (1) at high salt. The structure is a six-fold helix (n = 6) with height per residue, h = 7.25 1 similar to the crystal structure (2) of d(CG)5 (n = 6, h ~7.40 8). Asymmetric unit in both the cases is a dinucleotide, The structure of poly d(GC).poly d(GC) was reported to be very similar to that of d(CG)5. However, the prop...

The thermodynamics of rightand left-handed helix formation by poly[d(G-C)].poly[d(G-C)] and by poly(dG-mSdC).poly(dG-msdC) were measured spectrophotometrically and calorimetrically. From the spectrophotometric measurements the thermal stabilities of the alternative helical conformations were evaluated as a function of counterion concentration. From the calorimetric measurements the enthalpies o...