The conformational changes suffered by full-length double-stranded DNA molecules from bac­ teriophage T7, due to their binding with the mutagenic dye proflavine (PF), has been studied by electron microscopy. The dye-bound DNA showed a smoother contour and a more compact con­ figuration in comparison with the dye-free native DNA. These changes resulted from the stretching, extension and charge-n...

Electron microscopic and crystallographic data have shown that the gene 4 primase/helicase encoded by bacteriophage T7 can form both hexamers and heptamers. After cross-linking with glutaraldehyde to stabilize the oligomeric protein, hexamers and heptamers can be distinguished either by negative stain electron microscopy or electrophoretic analysis using polyacrylamide gels. We find that hexame...

Infrared spectroscopy was used to identify hydration-sensitive structural differences between single- stranded phosphorothioate (PS) and phosphodiester (PO) oligodeoxyribonucleotides. Spectra were recorded in the mid-infrared region, 500-1800 cm-1, at relative humidities between 0 and 98%; the PS and PO spectra are substantially different. The hydration effects on spectral bands in these single...

Materials and methods: In this study a total of 17 trophozoite samples, obtained either directly from stool samples or after excystation, or by duodenal aspiration, were used. A set of primers was chosen to amplify the different regions of triose phosphate isomerase (tpi) and a segment of the glutamate dehydrogenase (gdh) genes. A single-stranded conformational polymorphism technique was also u...

Debaprasad Giri, Sanjay Kumar and Yashwant Singh Department of Physics, Banaras Hindu University, Varanasi 221 005, India Centre for Theoretical Studies, IIT, Kharagpur 721 302, India (Dated: February 1, 2008) Abstract A model of self-avoiding walk with suitable constraints on self-attraction is developed to describe the conformational behaviour of a single stranded short DNA molecule that form...

Metal coordination is used to alter the oligomerization state of a designed peptide structure. The 30-residue polypeptide AQ-Pal14Pal21contains two metal-binding 4-pyridylalanine (Pal) residues on its solvent-exposed surface and exists as a very stable two-stranded alpha-helical coiled-coil. Upon the addition of Pt(en)(NO3)2, a significant conformational change to a metal-bridged, four-helix bu...

For biologically relevant macromolecules such as intrinsically disordered proteins, internal degrees of freedom that allow for shape changes have a large influence on both the motion and function compound. A detailed understanding effect flexibility is needed in order to explain their behavior. Here, we study model system freely-jointed chains three six colloidal spheres, using simulations expe...

gene delivery might be affected by several tribulations based on carrier/vector applied. bacteriophages lambda and m13 have different genome conformations; linear double-stranded and circular single-stranded respectively. therefore, it might be expected that these two common classes of gene delivery vehicles will have different capacity for gene delivery and expression in eukaryote cells. to ad...