Inhibition of HIV-1 by a peptide ligand of the genomic RNA packaging signal Psi.

The interaction of the nucleocapsid NCp7 of the human immunodeficiency virus type 1 (HIV-1) Gag polyprotein with the RNA packaging signal Psi ensures specific encapsidation of the dimeric full length viral genome into nascent virus particles. Being an essential step in the HIV-1 replication cycle, specific genome encapsidation represents a promising target for therapeutic intervention. We previously selected peptides binding to HIV-1 Psi-RNA or stem loops (SL) thereof by phage display.

Photo-CIDNP reveals differences in compaction of non-native states of lysozyme.

Photo-CIDNP effects interpreted for individual residues are used for the structural characterization of non-native ensembles of proteins, which is described in this paper. Two-dimensional photo-CIDNP experiments are compared to conventional HSQC spectra to elucidate the relative solvent exposure of the six tryptophan residues in non-native states of hen egg white lysozyme. The differential solvent accessibility of the tryptophan residues in non-native lysozyme coincides with the dynamical properties of these residues monitored for both backbone and side chain NH sides obtained from analysis of transverse relaxation measurements.