Extolling the benefits of molecular therapeutic lipidation

The conjugation of drug or molecular recognition motif to a hydrophobic fatty entity, for purpose of drug-membrane localization, has been a molecular strategy utilized for targeted inhibition of pathways involved in diseased cells. In general, membrane-anchored inhibitor structures have been composed of either a lipid or sterol group coupled via a broad range of inert linkers to either a peptide or small molecule protein recognition agent. Whilst not adhering to the molecular paradigms of modern medicinal chemistry, this approach has afforded peptidic-based therapeutics with improved cellular and in vivo efficacy, leading to more selective targeting of membrane associated protein targets and the effective immobilization of cytosolic signaling proteins through membrane anchorage. The evidence suggests that membrane-anchored peptidic inhibitors are more selective, potent, structurally rigid, and possess enhanced cell permeability profiles as compared to their non-lipidated precursors. This perspectives article will review the application of lipid or sterol conjugation to peptide inhibitors (lipo-molecules) to circumvent the poor cell permeability and metabolic labilities associated with peptidic therapeutics. In addition, the concept of protein-membrane anchorage as a novel drug modality for inhibiting cytosolic signaling protein motility in cells will be reviewed and its merits as an approach to inhibiting protein complexation, protein nuclear translocation and their potential for more effective targeting of membrane associated targets.