On a Bivariate XGamma Distribution Derived from Copula

In this paper, a new bivariate XGamma (BXG) distribution is presented using Farlie-Gumbel-Morgenstern (FGM) copula. We derive the expressions for conditional distribution, regression function and product moments for the BXG distribution. Concept of reliability and various measures of local dependence are also studied for the proposed model. Furthermore, estimation of the parameters of the BXG distribution is obtained through maximum likelihood estimation and inference function of margin estimation procedures. Finally, an application of the same is also demonstrated to a real data set

Selective recognition of human telomeric G-quadruplex with designed peptide:Via hydrogen bonding followed by base stacking interactions

We described a novel synthetic peptide in which a glutamine residue binds through hydrogen bonding to a guanine-base and a trytophan residue intercalates with K(+) resulting in stabilization of a human telomeric G-quadruplex with high selectivity over its complementary c-rich strand and a double-stranded DNA and its complementary C-rich strand. This peptide offers great potential for cancer treatment by inhibiting the telomere extension by telomerase

Metal sensitive and DNA concentration dependent structural rearrangement of short oligonucleotide into large suprastructures

<p>Formation of higher order structures, such as G-quadruplexes and G-quadruplex based large suprastructures into long G-wires and liquid crystals is promising elements for use in healthcare for drug delivery as they are mechanically and thermally stable. In this study, we studied the structures of short 11-mer oligonucleotide 5′-G₂AG₅AG₂-3′(11Pu) which is observed in 3′-UTR region of c-jun protooncogene. We used circular dichroism, UV-thermal melting, native gel electrophoresis and atomic force microscopy to determine the structure of 11Pu. CD results showed that 11Pu formed a mixed G-quadruplex in the presence of Na⁺ with and without Mg²⁺, while it formed a parallel G-quadruplex in the presence of 100 mM K⁺ with or without Mg²⁺. Cation selectivity in inducing the formation of large superstructures was observed in the presence of 100 mM K⁺ with 10 mM Mg²⁺. On the contrary, 10 mM Ca²⁺ did not induce the suprastructures. It was further demonstrated that Mg²⁺ at low concentration induced a parallel G-quadruplex of 11Pu, whereas at 10 mM Mg²⁺ induced a large suprastructure. AFM Images showed that 11Pu formed a G-wire, a liquid crystals and a crystalline lattice depending on the concentration of 11Pu and Mg²⁺. These insights may be employed to design G quadruplex-based nanowires for targeted drug delivery as well as interesting candidates for molecular nanowires.</p> <p>Communicated by Ramaswamy H. Sarma</p