No abstract

Recent studies have shown that chemically synthesized small peptides can induce antibodies that often react with intact proteins regardless of their position in the folded molecule. These findings are difficult to explain in view of the experimental and theoretical data which suggest that in Recent studies have shown that antibodies to short peptides often cross-react with intact proteins irrespective of where the peptide is located on the surface of the intact structure (reviewed in refs. 1 and 2). The initial assumption was that these peptides adopted many conformations in solution, occasionally assuming one that approximated its cognate structure in the native molecule (3). Thus, an anti-peptide antiserum could be thought of as a collection of antibodies to different conformations, with some percentage reactive with conformations shared by the folded protein. However, the problem with this assumption is that in the absence of forces engendered by neighboring structures, peptides are thought to have a vast number of conformations, and one would predict a relatively low success rate of generating antibodies reactive with intact proteins when a large number of different peptides are tried. This prediction turns out not to be true because a large number of different protein-reactive anti-peptide antibodies have been generated in the last 2 yr (1-3). There are alternative explanations that could explain the high rate of success with which short peptides induce protein-reactive antibodies.

Background: The novel A/H1N1 influenza virus, which recently emerged in North America is most closely related to North American H1N1/N2 swine viruses. Until the beginning of 2009, North American swine H1N1/N2 viruses have only sporadically infected humans as dead-end hosts. In 2009 the A/H1N1 virus acquired the capacity to spread efficiently by human to human transmission. The novel A/H1N1 influenza virus has struck thousands of people in more than 70 countries and killed more than 140, representing a public health emergency of international concern. Here we have studied properties of hemagglutinin of A/H1N1 which may modulate virus/ receptor interaction.

We previously determined the nucleotide sequence of the 3' end of Moloney leukaemia virus and discovered the potential coding region for an unknown protein, R. We now show that this region does encode a protein. A pentadecapeptide of R was chemically synthesized and antibodies raised against it. Antisera to the synthetic peptide recognize the R protein and the env precursor polyprotein in infected cells. The strategy presented here should provide a general method for accessing proteins predicted by nucleotide sequences.