Slide 1

Glycans in the Biotechnology and Pharmaceutical Industries Lecture 42 Carolyn R. Bertozzi UC Berkeley Slide 2 Lecture Outline 1.Examples of approved carbohydrate-based drugs 2.Development of drugs to treat influenza 3.Development of selectin inhibitors for inflammation 4.Imino-sugars as drug candidates for storage diseases Slide 3 Examples of approved carbohydrate drugs: SubstanceIndicationCompany AcarboseDiabetesBayer AG AMVISCOpthalamic surgeryAnika Therapeutics HyalganOsteoarthritisFIDIA/Sanofi LovenoxCardiovascular diseaseAventis MiglitolDiabetesBayer AG ORTHOVISCOsteoarthritisAnika Therapeutics RelenzaInfluenzaGlaxo Smithkline TamifluInfluenzaRoche SOLARASEActinic keratosisHyal Pharmaceuticals TopamaxEpilepsyJ & J VogliboseDiabetesTakedo/Abbott Slide 4 Examples of carbohydrate-based drugs Slide 5 Examples of glycosylated natural products Slide 6 Examples of approved glycoprotein drugs: SubstanceCompany ErythropoietinAmgen, J&J Tissue plasminogen activatorGenentech Interleukin-2Chiron CerezymeGenzyme Monoclonal antibodiesMany From: Hudson, P. J.; Souriau, C. Nature Medicine 2003, 9, 129-134 Slide 7 Lecture Outline 1.Examples of approved carbohydrate-based drugs 2.Development of drugs to treat influenza 3.Development of selectin inhibitors for inflammation 4.Imino-sugars as drug candidates for storage diseases Slide 8 Cell surface oligosaccharides are determinants of cell recognition bacterium cell virus toxin hormone glycoprotein Slide 9 Microbial pathogens bind to cell surface sugars as a first step during infection Influenza virus - Flu HIV - AIDS Helicobacter pylori - Ulcers Escherichia coli - Meningitis Pseudomonas aeruginosa - Pneumonia Trypanosomes - African sleeping sickness Plasmodium falciparum - Malaria Slide 10 The influenza virus has two membrane-associated proteins, hemagglutinin and neuraminidase Hemagglutinin binds sialic acid (receptor) Neuraminidase cleaves sialic acid (enzyme) Host cell Sialic acid (SA) Slide 11 SA Hemagglutinin binds sialic acid to initiate infection Host cell Endocytosis Membrane fusion and release of viral particle Replication SA New viruses assemble at membrane SA Neuraminidase cleaves sialic acid and liberates new virus Life cycle of the influenza virus Slide 12 Sialic acid analogs block influenza virus infection Cell Sialic acid influenza virus C-Glycoside of sialic acid Slide 13 E a (cat) E a (uncat) Enzymes catalyze reactions by preferential binding of the transition state vs the ground state Transition state analogs are potent enzyme inhibitors Slide 14 Slide 15 Design of transition state analog neuraminidase inhibitors Planarity (sp 2 ) 2,3-Anhydro sialic acid K i = 10 -6 M Also inhibits human neuraminidase Slide 16 Tamiflu (Hoffman La Roche) K i = 10 -10 M Relenza (Glaxo Smithkline) K i = 10 -10 M Structure-based design of more potent and selective neuraminidase inhibitors Binding pocket of Flu neuraminidase based on X-ray structure Slide 17 Lecture Outline 1.Examples of approved carbohydrate-based drugs 2.Development of drugs to treat influenza 3.Development of selectin inhibitors for inflammation 4.Imino-sugars as drug candidates for storage diseases Slide 18 Blood vessel Activated endothelium Tissue Leukocyte A hallmark of inflammation is the recruitment of leukocytes from the bloodstream into surrounding tissues Slide 19 The initial attachment of leukocytes to endothelial cells at sites of inflammation is mediated by the selectins Leukocyte Endothelial cell L-selectin E-selectin P-selectin Slide 20 Inflammatory diseases involving the selectins: 1. Rheumatoid arthritis 2. Asthma 3. Transplant rejection 4. Psoriasis 5. Inflammatory bowel disease 6. Ischemia/reperfusion injury 7. Diabetes 8. Multiple sclerosis 9. Many more.. Inhibitors of selectin-mediated cell adhesion would be broad spectrum anti-inflammatory agents Slide 21 Slide 22 Slide 23 Limitations of sLe x as a therapeutic agent Lack of potency Poor pharmacokinetics Difficult and expensive synthesis Possible solutions Glycomimetics Oligomerization Glycoprotein constructs Slide 24 Slide 25 Slide 26 (in clinical development at Texas Biotech.) Slide 27 Limitations of sLe x as a therapeutic agent Lack of potency Poor pharmacokinetics Difficult and expensive synthesis Possible solutions Glycomimetics Oligomerization Glycoprotein constructs Slide 28 Slide 29 Nagy and coworkers Slide 30 Kiessling and coworkers Slide 31 Limitations of sLe x as a therapeutic agent Lack of potency Poor pharmacokinetics Difficult and expensive synthesis Possible solutions Glycomimetics Oligomerization Glycoprotein constructs Slide 32 Approaches to selectin inhibitors inspired by the discovery of their biological ligands Slide 33 Structure of the biological selectin ligands Slide 34 Determinants of PSGL-1 required for P-selectin binding Slide 35 A potent P-selectin inhibitor based on PSGL-1: Recombinant PSGL-Ig (TS-1) Features: Good potency (nM K d ) Good PK (serum 1/2-life = 2-3 wks) Also inhibits L-selectin Human IgG1 Fc (inactivated) 47 N-terminal residues from PSGL-1 Slide 36 Leukocyte L-Selectin { Endothelial cell Leukocyte adhesion to endothelial cells is mediated by L-selectin binding to sulfated sialyl Lewis x 6-Sulfo sialyl Lewis x Slide 37 Slide 38 Lecture Outline 1.Examples of approved carbohydrate-based drugs 2.Development of drugs to treat influenza 3.Development of selectin inhibitors for inflammation 4.Imino-sugars as drug candidates for storage diseases Slide 39 Defects in glycolipid degradation lead to lysosomal storage disorders From: Dwek, R. A., et al. Nature Rev. Drug Disc. 2001, 1, 65-75. Slide 40 Imino-sugars can block biosynthesis of glycolipid precursors Slide 41 Slide 42 Numerous companies have been founded on glycobiology platforms