Recognition of envelope and tat protein synthetic peptide analogs by HIV positive sera or plasma

AbstractA series of synthetic peptides corresponding to segments of HIV encoded proteins were selected using criteria described by Welling et al. [(1985) FEBS Lett. 188, 215]. Synthetic peptide analogs to gpl20 (2–13), (55–65), gp41 (582–596) (659–670) and tatIII (71–83) were recognized by 41–67% of sera or plasma from individuals known to be infected with HIV on the basis of virus isolation or Western blot screening. The peptide which reacted with most sera or plasma was gp41 (582–596), a conserved region in the transmembrane glycoprotein. An extended peptide analog, gp41 (579–599), tested against the same samples showed almost 100% reactivity, confirming independent studies identifying a highly immunodominant region of gp41. There was an unexpected high prevalence of antibodies (52%) to the tatIII peptide

Nuclear Magnetic Resonance Spectroscopy. Spin-Lattice Relaxation of the Acetic Acid Carboxyl Carbon

The carbon-13 spin-lattice relaxation times of the carboxyl carbons of acetic acid and its deuterated analogues (CH_3COOD, CD_3COOH, CD_3COOD) have been measured by nuclear magnetic resonance spectroscopy. These measurements reveal that the methyl protons and the hydroxyl proton contribute roughly equally to the total dipolar relaxation of neat acetic acid. Spin-rotation relaxation is also observed in these molecules. The T_1 and NOE values for the carboxyl carbon of acetic acid in aqueous solution each demonstrate a small concentration dependence in the region of high acid concentration. Although samples of 1 M acetic acid contaminated with paramagnetic metal ions show a marked pH dependence of T_1 and NOE, the T_1and NOE values for purified samples are invariant with respect to pH. Some chemical implications of the above behavior are discussed

The global circulation of seasonal influenza A (H3N2) viruses.

Antigenic and genetic analysis of the hemagglutinin of approximately 13,000 human influenza A (H3N2) viruses from six continents during 2002-2007 revealed that there was continuous circulation in east and Southeast Asia (E-SE Asia) via a region-wide network of temporally overlapping epidemics and that epidemics in the temperate regions were seeded from this network each year. Seed strains generally first reached Oceania, North America, and Europe, and later South America. This evidence suggests that once A (H3N2) viruses leave E-SE Asia, they are unlikely to contribute to long-term viral evolution. If the trends observed during this period are an accurate representation of overall patterns of spread, then the antigenic characteristics of A (H3N2) viruses outside E-SE Asia may be forecast each year based on surveillance within E-SE Asia, with consequent improvements to vaccine strain selection