Voltage dependent closure of PorB class II porin from Neisseria meningitidis investigated using impedance spectroscopy in a tethered bilayer lipid membrane interface.

Electrochemical impedance spectroscopy (EIS) was used to characterize voltage-dependent closure of PorB class II (PorBII) porin from Neisseria meningitidis incorporated in a tethered bilayer lipid membrane (tBLM). The tBLM's lower leaflet was fabricated by depositing a self assembled monolayer (SAM) of 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) on a gold electrode, and the upper leaflet was formed by depositing1,2-dioleoyl-sn-glycero-3-phoshocholine (DOPC) liposomes. At 0mV bias DC potential, incorporation of PorBII decreased the membrane resistance (R(m)) from 2.

A novel route for immobilization of oligonucleotides onto modified silica nanoparticles.

A novel approach for immobilization of probe oligonucleotides that uses zirconium phosphate modified silica nanoparticles is proposed. The surface modification of nanoparticles was carried out in two stages. Initially binding of Zr4+ to the surface of silica nanoparticles and later treated with phosphoric acid for terminal phosphate groups.

A novel method for synthesis of silica nanoparticles.

A sequential method has been used, for the first time, to prepare monodisperse and uniform-size silica nanoparticles using ultrasonication by sol-gel process. The silica particles were obtained by hydrolysis of tetraethyl orthosilicate (TEOS) in ethanol medium and a detailed study was carried out on the effect of different reagents on particle sizes. Various-sized particles in the range 20-460 nm were synthesized.

Differential transcriptional regulation of two distinct S-adenosylmethionine synthetase genes (SAM1 and SAM2) of Saccharomyces cerevisiae.

Expression of a number of genes encoding enzymes involved in phospholipid biosynthesis in yeast Saccharomyces cerevisiae is known to be repressed on the addition of myo-inositol and choline to the culture medium (inositol-choline regulation). All genes subject to this inositol-choline regulation have an octamer sequence 5'-CATRTGAA-3' in their upstream regions and those octamer sequences play an important role in this regulation. To confirm the role of the octamer sequence further, we studied the transcriptional regulation of two distinct S-adenosylmethionine synthetase genes (SAM1 and SAM2) of S.