520 likes | 809 Views
Glycans in the Biotechnology and Pharmaceutical Industries Lecture 42 Carolyn R. Bertozzi UC Berkeley. Lecture Outline Examples of approved carbohydrate-based drugs Development of drugs to treat influenza Development of selectin inhibitors for inflammation
E N D
Glycans in the Biotechnology and Pharmaceutical Industries Lecture 42 Carolyn R. Bertozzi UC Berkeley
Lecture Outline • Examples of approved carbohydrate-based drugs • Development of drugs to treat influenza • Development of selectin inhibitors for inflammation • Imino-sugars as drug candidates for storage diseases
Examples of approved carbohydrate drugs: Substance Indication Company Acarbose Diabetes Bayer AG AMVISC Opthalamic surgery Anika Therapeutics Hyalgan Osteoarthritis FIDIA/Sanofi Lovenox Cardiovascular disease Aventis Miglitol Diabetes Bayer AG ORTHOVISC Osteoarthritis Anika Therapeutics Relenza Influenza Glaxo Smithkline Tamiflu Influenza Roche SOLARASE Actinic keratosis Hyal Pharmaceuticals Topamax Epilepsy J & J Voglibose Diabetes Takedo/Abbott
From: Hudson, P. J.; Souriau, C. Nature Medicine2003, 9, 129-134 Examples of approved glycoprotein drugs: Substance Company Erythropoietin Amgen, J&J Tissue plasminogen activator Genentech Interleukin-2 Chiron Cerezyme Genzyme Monoclonal antibodies Many
Lecture Outline • Examples of approved carbohydrate-based drugs • Development of drugs to treat influenza • Development of selectin inhibitors for inflammation • Imino-sugars as drug candidates for storage diseases
bacterium virus cell toxin hormone Cell surface oligosaccharides are determinants of cell recognition glycoprotein
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
The influenza virus has two membrane-associated proteins, hemagglutinin and neuraminidase Neuraminidase cleaves sialic acid (enzyme) Hemagglutinin binds sialic acid (receptor) Sialic acid (SA) Host cell
Neuraminidase cleaves sialic acid and liberates new virus New viruses assemble at membrane Endocytosis Membrane fusion and release of viral particle Replication Life cycle of the influenza virus SA Hemagglutinin binds sialic acid to initiate infection SA SA SA Host cell SA SA
influenza virus Sialic acid analogs block influenza virus infection Sialic acid Cell “C-Glycoside” of sialic acid
Ea (uncat) Ea (cat) Transition state analogs are potent enzyme inhibitors Enzymes catalyze reactions by preferential binding of the transition state vs the ground state
Planarity (sp2) 2,3-Anhydro sialic acid Ki = 10-6 M Also inhibits human neuraminidase Design of transition state analog neuraminidase inhibitors ‡
Binding pocket of Flu neuraminidase based on X-ray structure Relenza (Glaxo Smithkline) Ki = 10-10 M Tamiflu (Hoffman La Roche) Ki = 10-10 M Structure-based design of more potent and selective neuraminidase inhibitors
Lecture Outline • Examples of approved carbohydrate-based drugs • Development of drugs to treat influenza • Development of selectin inhibitors for inflammation • Imino-sugars as drug candidates for storage diseases
A hallmark of inflammation is the recruitment of leukocytes from the bloodstream into surrounding tissues Tissue Blood vessel Leukocyte Activated endothelium
The initial attachment of leukocytes to endothelial cells at sites of inflammation is mediated by the selectins Leukocyte L-selectin E-selectin P-selectin Endothelial cell
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
Limitations of sLex as a therapeutic agent • Lack of potency • Poor pharmacokinetics • Difficult and expensive synthesis Possible solutions • Glycomimetics • Oligomerization • Glycoprotein constructs
Limitations of sLex as a therapeutic agent • Lack of potency • Poor pharmacokinetics • Difficult and expensive synthesis Possible solutions • Glycomimetics • Oligomerization • Glycoprotein constructs
Limitations of sLex as a therapeutic agent • Lack of potency • Poor pharmacokinetics • Difficult and expensive synthesis Possible solutions • Glycomimetics • Oligomerization • Glycoprotein constructs
Approaches to selectin inhibitors inspired by the discovery of their biological ligands
Determinants of PSGL-1 required for P-selectin binding
A potent P-selectin inhibitor based on PSGL-1:Recombinant PSGL-Ig (TS-1) 47 N-terminal residues from PSGL-1 Human IgG1 Fc (inactivated) Features: • Good potency (nM Kd) • Good PK (serum 1/2-life = 2-3 wks) • Also inhibits L-selectin
Leukocyte adhesion to endothelial cells is mediated by L-selectin binding to sulfated sialyl Lewis x Leukocyte 6-Sulfo sialyl Lewis x L-Selectin { Endothelial cell
Lecture Outline • Examples of approved carbohydrate-based drugs • Development of drugs to treat influenza • Development of selectin inhibitors for inflammation • Imino-sugars as drug candidates for storage diseases
Defects in glycolipid degradation lead to lysosomal storage disorders From: Dwek, R. A., et al.Nature Rev. Drug Disc. 2001, 1, 65-75.
Imino-sugars can block biosynthesis of glycolipid precursors
Numerous companies have been foundedon glycobiology platforms