Human Onchocerca volvulus infection sera were found to recognize zwitterionic glycolipids of O. volvulus and to cross-react with those of other parasitic nematodes (Ascaris suum, Setaria digitata and Litomosoides sigmodontis). By the use of an epitope-specific monoclonal antibody, zwitterionic glycolipids of all these nematode species were observed to contain the antigenic determinant phosphoch...

Defects are often considered as the active sites for chemical reactions. Here a variety of defects in zeolites are used to stabilize zwitterionic glycine that is not self-stable in gas phase; in addition, effects of acidic strengths and zeolite channels on zwitterionic stabilization are demonstrated. Glycine zwitterions can be stabilized by all these defects and energetically prefer to canonica...

Although Bacteroides fragilis accounts for only 0.5% of the normal human colonic flora, it is the anaerobic species most frequently isolated from intra-abdominal and other infections with an intestinal source. The capsular polysaccharides of B. fragilis are part of a complex of surface polysaccharides and are the organism's most important virulence factors in the formation of intra-abdominal ab...

In the present study, 13-residue peptides with sequences corresponding to the native N-terminal segment of pulmonary SP-C (surfactant protein C) have been synthesized and their interaction with phospholipid bilayers characterized. The peptides are soluble in aqueous media but associate spontaneously with bilayers composed of either zwitterionic (phosphatidylcholine) or anionic (phosphatidylglyc...

The gas-phase structures of protonated and alkali metal cationized arginine (Arg) and arginine methyl ester (ArgOMe) are investigated with infrared spectroscopy and ab initio calculations. Infrared spectra, measured in the hydrogen-stretch region, provide compelling evidence that arginine changes from its nonzwitterionic to zwitterionic form with increasing metal ion size, with the transition i...

Complexes formed by the imidazolium cation and the aromatic amino acids, phenylalanine, tyrosine, tryptophan, and histidine have been studied by using computational methods. Complexation energies estimated at the MP2.X level amount to -123.3, -124.6, -131.5 and -145.5 kJ mol(-1) for Phe, Tyr, Trp and His, respectively. The results obtained for Phe, Tyr and Trp complexes are similar, with the mo...

Human African Trypanosomiasis (HAT) is a neglected parasitic disease that continues to persist in sub-Saharan Africa. It fatal if untreated. The first stage of the associated with presence parasite periphery and second parasites CNS. treatment CNS HAT requires drugs cross blood-brain barrier (BBB). Eflornithine an amino acid analogue used treat gambiense both alone combination nifurtimox. Recen...

We developed novel zwitterionic near infrared (NIR) fluorescent agents (ABZWCY-HPbCD and AAZWCYHPbCD), which exhibit favorable hydrophilicity, low plasma protein binding, high stability and nontoxicity. These attractive characteristics ensure that they are excreted rapidly, without any skin accumulation or metabolism in vivo. More importantly, zwitterionic HPbCD based agents can be efficiently ...

BACKGROUND Inorganic nanoparticles provide promising tools for biomedical applications including detection, diagnosis and therapy. While surface properties such as charge are expected to play an important role in their in vivo behavior, very little is known how the surface chemistry of nanoparticles influences their pharmacokinetics, tumor uptake, and biodistribution. METHOD/PRINCIPAL FINDING...