Glycopeptide Drugs from the Brain for the Brain
Robin Polt
Professor, Univeristy of Arizona
Studies with O-linked glycopeptide drug candidates suggest that two conformational ensembles exist– A highly flexible group of water soluble structures (random coils), and a much smaller set of “amphipathic states” that are more constrained, and membrane-bound. Most if not all endogenous neuropeptides possess strong amphipathic character that constrain them to membrane surfaces. Pioneering studies with enkephalins and endorphin/dynorphin analogues suggest that the modulation of membrane affinity by glycosylation (or the introduction of other water-soluble moieties) produces “biousian glycopeptides” that are systemically available (favorable PK/PD), and can cross the BBB.
Glycopeptides are expected to be useful in the treatment of diverse neurological conditions, including chronic pain, recovery from stroke and/or traumatic brain injury, and numerous neurodegenerative disease states, including Parkinson’s disease, Alzheimer’s disease and Huntington’s chorea, as well as the treatment of pain. The innovative feature of these drugs is the fact that the CNS drugs are derived from endogenous peptide hormones and neurotransmitters that already possess the proper anatomical distribution and therapeutic potential to treat neurological diseases and syndromes. Our designs incorporate the potency and selectivity of the endogenous peptides into the glycopeptide drug candidates, assuring that only the targeted receptors (GPCRs) are activated. Additionally, the glycopeptides are metabolized into sugars and amino acids that are pharmacologically inert, and may be properly regarded as nutrients, rather than toxic metabolites. At this point in time we have successfully converted enkephalins, endorphins, angiotensins, oxytocins and secretins into brain-penetrant glycopeptide drug candidates.
Exciting new results will be presented that show the disease-modifying effects of glycopeptide drugs in vivo.
Robin Polt earned his Ph.D. from Gilbert Stork at Columbia University in 1986. Since then he has developed new synthetic methods for the synthesis of novel amino acids, alkaloids, glycolipids and glycosides that modulate the interaction of drug candidates with biological membranes. Currently, his research group is focused on glycopeptide drugs based on endogenous peptide hormones, and is one of the founders of Teleport Pharmaceuticals.