The structure of the Rous sarcoma virus envelope glycoprotein complex was studied by sedimentation gradient centrifugation analyses of detergent-solubilized wild-type and mutant envelope (env) gene products. These studies show that the envelope glycoprotein forms an oligomer during biosynthesis, which is most likely a trimer, and that this is the form of the complex found in virions. Our result...

Pertussis toxin (PTX) is a typical A-B toxin. The A-protomer (S1 subunit) exhibits ADP-ribosyltransferase activity. The B-oligomer consists of four subunits (S2 to S5) and binds extracellular molecules that allow the toxin to enter the cells. The A-protomer ADP-ribosylates the α subunits of heterotrimeric G(i/o) proteins, resulting in the receptors being uncoupled from the G(i/o) proteins. The ...

Pertussis toxin, both complete and the B-oligomer, were imaged by atomic force microscopy (AFM), using specimens prepared by simple surface adsorption on mica without further manipulation. The spatial arrangement of the subunits of the B-oligomer was clearly resolved, representing the first protein quaternary structure obtained by AFM in situ. The results suggest that the B-oligomer is a flat p...

2,6-Diaminopurine and 5-chloro-uracil 2'-deoxynucleoside 5'-triphosphates were synthesized from their 2'-deoxynucleosides. Using a method of creating oligonucleotides by enzymatic primer extension, dodecanucleotides representing an XbaI/SalI site and the complementary SalI/XbaI site were generated containing these base modifications. Their duplex stability was quantitatively compared by thin-la...

Recently, we reported that the nanowell array (NWA) enhances electrochemical responses during the binding event of molecule to molecule through the binding site control of captured molecule. In this paper, we have demonstrated a method, with high sensitivity and selectivity for single nucleotide polymorphism detection of leptin, which is an established obesity biomarker. A 21-mer probe was immo...

A capillary zone electrophoresis (CZE) approach was developed for the determination of hexamethylene diisocyanate (HDI) monomer and HDI-based oligomers. A comparison of CZE with high performance liquid chromatography (HPLC) indicates that the CZE separation completely isolates isocyanates from excess solvent, derivatizing reagent and pigment while offering a fivefold increase in sensitivity. Th...

A novel hierarchy of coarse-grain, sequence-dependent, rigid-base models of B-form DNA in solution is introduced. The hierarchy depends on both the assumed range of energetic couplings, and the extent of sequence dependence of the model parameters. A significant feature of the models is that they exhibit the phenomenon of frustration: each base cannot simultaneously minimize the energy of all o...

In this paper we report on a combination of experimental and theoretical study of a new copolymer based on carbazole and methylthiophene (Cbz-Mth), in their neutral and oxidized states. We discuss the influence of chain length on conformational and optoelectronic properties with the DFT method. Conformational analysis shows that there are no big changes in the structural parameters of neutral o...

The preparation of t-butoxycarbonyl (Boc)-protected O(4)-(o-nitrophenyl) thymine peptide nucleic acid (PNA) monomer is described. This PNA monomer was incorporated into PNA oligomer sequences. The post-synthetic modification of the oligomers to yield fluorescently-labelled PNA oligomers was studied before and after the removal of the protecting groups. In both cases, the desired fluorescently-l...