The MDM2-binding region in the transactivation domain of p53 also acts as a Bcl-X(L)-binding motif.

While the transcription-dependent mechanism of p53 has been extensively studied, recently the transcription-independent apoptotic activity of p53 has also been described. Bcl-2 and Bcl-X(L) interact with p53 and induce apoptosis. Initially, the p53 DNA-binding domain (p53DBD) was found to bind to Bcl-2 and Bcl-X(L).

Quaternary protein mimetics of gp41 elicit neutralizing antibodies against HIV fusion-active intermediate state.

During viral entry, the fusogenic state of human immunodeficiency virus Type 1 (HIV-1) envelope protein gp41 is a quaternary structure consisting of three gp41 glycoproteins, each with two conserved helical domains (N-HR and C-HR). Thus far, the examination of monomeric gp41 peptides as an immunologically focused approach to vaccine design has not been successful. Here we report an approach using quaternary protein mimetics (called 3alpha mimetics) that are based on the gp41 N-HR and C-HR domains to closely mimic the fusogenic state and overcome the deficiencies of the monomeric peptide approach for synthetic vaccine design.

Selection of active ScFv to G-protein-coupled receptor CCR5 using surface antigen-mimicking peptides.

This study describes the use of cyclic peptides for use in the selection of single-chain (ScFv) antibodies specific for the HIV-1 coreceptor CCR5, a representative G-protein-coupled receptor (GPCR). A tandem ligation strategy was developed for preparing biotinylated cyclic peptides, first through an orthogonal end-to-end ligation and then a chemoselective ligation with functionalized biotin. Cyclic peptides mimicking the extracellular loops of CCR5 and their unconstrained counterparts were then used for solution-phase selection of ScFv antibodies from a phage display antibody library.

Translocating proline-rich peptides from the antimicrobial peptide bactenecin 7.

The intracellular delivery of most peptides, proteins, and nucleotides to the cytoplasm and nucleus is impeded by the cell membrane. To allow simplified, noninvasive delivery of attached cargo, cell-permeant peptides that are either highly cationic or hydrophobic have been utilized. Because cell-permeable peptides share half of the structural features of antimicrobial peptides containing clusters of charge and hydrophobic residues, we have explored antimicrobial peptides as templates for designing cell-permeant peptides.

Peptide dendrimers: applications and synthesis.

Peptide dendrimers are radial or wedge-like branched macromolecules consisting of a peptidyl branching core and/or covalently attached surface functional units. The multimeric nature of these constructs, the unambiguous composition and ease of production make this type of dendrimer well suited to various biotechnological and biochemical applications. Applications include use as biomedical diagnostic reagents, protein mimetics, anticancer and antiviral agents, vaccines and drug and gene delivery vehicles.