Hb Sallanches [alpha104(G11)Cys-->Tyr, TGC>TAC] occurs frequently on the Indian subcontinent.

Point mutations of alpha-globin genes in homozygous or in compound heterozygous states cause severe alpha-thalassemia (alpha-thal). Here we describe a polymerase chain reaction-restriction fragment length polymorphism-based method for easy detection of the point mutation Hb Sallanches [alpha104(G11)Cys-->Tyr, TGC>TAC], earlier detected by a sequencing technique. In a cohort of 104 unrelated putative alpha-thal patients, nine carried the mutation and two were homozygotes. The mutation occurred on both the alpha2- or alpha1-globin genes. The phenotypes, in conjunction with other point mutations or deletions, are presented. Earlier detected in Pakistan and Punjab of India, it is probably present all over the Indian subcontinent.

Alprazolam intercalates into DNA.

In vitro interaction of a benzodiazepine group of drugs Alprazolam (Alp), a hypnotic and tranquilizer, with DNA was studied by various methods. Absorption spectrophotometric study showed that Alp binds strongly with supercoiled pUC 19 DNA and the calculated binding constant is 8.245x10(3) M(-1) in 10 mM Tris-Cl buffer, pH 7.4. Spectrofluorometric study showed that ethidium bromide induced DNA fluorescence intensity was reduced completely after addition of Alp. But Alp did not interfere with the interaction of Hoechst 33258, a DNA minor groove binder, with plasmid DNA. Circular dichroic spectroscopic study showed that with the gradual increase in Alp concentrations, both the positive and the negative peaks of DNA were gradually decreased and at higher concentrations of Alp (60 microM and 80 microM), the negative peaks became positive indicating the intercalation and the conformational change in the DNA. Binding of Alp with DNA increased the thermal stability of DNA by 6 degrees C with respect to the mock treated sample. Gel electrophoresis study of supercoiled pUC 19 DNA showed more compact structure as a result of Alp binding. Transmission electron microscopic observations also confirmed this compactness. Thus, our observations suggest the strong interaction of Alp with DNA, which may raise serious questions about the random uses of Alprazolam.

Interaction of hemoglobin and copper nanoparticles: implications in hemoglobinopathy.

Here we study the interaction of copper nanoparticles (CuNPs) with different variants of hemoglobin (Hb). The study reports analysis with HbA0 (the major component of human Hb) and HbA2 (a variant that is associated with beta-thalassemia). In the case of HbA0, the major fraction of human Hb, the CuNPs trigger protein aggregation, and this is followed by the precipitation of the protein. The aggregative response is largely attenuated in the case of HbA2. The difference between the two variants is thus amenable to detection by simple optical methods. We verified that CuNPs co-precipitated with specific Hb variants using atomic absorption spectroscopy (AAS) and high-pressure liquid chromatography (HPLC). An associated observation was the reversal of zeta potential of HbA0 induced by the CuNPs (from -11 mV to +13 mV). Dynamic light-scattering (DLS) studies indicated that in the case of HbA0, protein initially broke the nanoclusters into smaller sizes (4 nm), and this was followed by a gradual increase in cluster size. Assays of heme peroxidase activity indicated that the protein unfolded during the process. It is suggested that interaction between the CuNPs and HbA0 stimulates the molten-globule state of the protein, leading to the onset of such an aggregative pathway. When studied for other variants, HbE, a common mutant of Hb, showed similar aggregative behavior, and on the other hand, rare variants such as HbC tended to remain in solution. A suitable scaling up of the approach may have important implications in screening hemoglobinopathies such as beta-thalassemia.