Design, synthesis and in vitro evaluation of novel bivalent S-adenosylmethionine analogues.

In optimal cases, bivalent ligands can bind with exceptionally high affinity to their protein targets. However, designing optimised linkers, that orient the two binding groups perfectly, is challenging, and yet crucial in both fragment-based ligand design and in the discovery of bisubstrate enzyme inhibitors. To further our understanding of linker design, a series of novel bivalent S-adenosylmethionine (SAM) analogues were designed with the aim of interacting with the MetJ dimer in a bivalent sense (1:1 ligand/MetJ dimer).

Multi-Tox: application of the ToxR-transcriptional reporter assay to the study of multi-pass protein transmembrane domain oligomerization.

ToxR-based transcriptional reporter assays allow the strength of transmembrane helix interactions in biological membranes to be measured. Previously, these assays have only been used to study single-pass transmembrane systems. To facilitate investigation of polytopic transmembrane domain (TMD) oligomerization, we applied the ToxR methodology to the study of multi-pass TMD oligomerization to give 'Multi-Tox'.

Transmembrane domain oligomerization propensity determined by ToxR assay.

The oversimplified view of protein transmembrane domains as merely anchors in phospholipid bilayers has long since been disproven. In many cases membrane-spanning proteins have evolved highly sophisticated mechanisms of action. One way in which membrane proteins can modulate their structures and functions is by direct and specific contact of hydrophobic helices, forming structured transmembrane oligomers.

Transmembrane peptides used to investigate the homo-oligomeric interface and binding hotspot of latent membrane protein 1.

Epstein-Barr virus (EBV), a human γ-herpesvirus, establishes lifelong infection by targeting the adaptive immune system of the host through memory B cells. Although normally benign, EBV contributes to lymphoid malignancies and lymphoproliferative syndromes in immunocompromised individuals. The viral oncoprotein latent membrane protein 1 (LMP-1) is essential for B lymphocyte immortalization by EBV.

Application of a novel in silico high-throughput screen to identify selective inhibitors for protein-protein interactions.

Increasing numbers of target protein structures available for computational studies makes the structure-based screening paradigm more attractive for initial hit indentification. We have developed a novel in silico screening methodology incorporating Molecular Mechanics (MM)/implicit solvent methods to evaluate binding free energies and applied this technology to the identification of inhibitors of the TLR4/MD-2 interaction.

Identification of stable S-adenosylmethionine (SAM) analogues derivatised with bioorthogonal tags: effect of ligands on the affinity of the E. coli methionine repressor, MetJ, for its operator DNA.

The efficient synthesis of a range of stable SAM mimetics, and their ability to promote the binding of the E. coli methionine repressor (MetJ) to its operator DNA, is described.

Configurational stability of bisindolylmaleimide cyclophanes: from conformers to the first configurationally stable, atropisomeric bisindolylmaleimides.

The bisindolylmaleimides are selective protein kinase inhibitors that can adopt two limiting diastereomeric (syn and anti) conformations. The configurational stability of a range of substituted and macrocyclic bisindolylmaleimides was investigated by using appropriate techniques. With unconstrained bisindolylmaleimides, the size of the 2-indolyl substituents was found to affect configurational stability, though not sufficiently to allow atropisomeric bisindolylmaleimides to be obtained.