1. Glycans in the Biotechnology and Pharmaceutical Industries
Lecture 42
Carolyn R. Bertozzi
UC Berkeley

2. 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

3. 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

4. Examples of carbohydrate-based drugs

5. Examples of glycosylated natural products

6. Examples of approved glycoprotein drugs:
Substance Company
Erythropoietin Amgen, J&J
Tissue plasminogen activator Genentech
Interleukin-2 Chiron
Cerezyme Genzyme
Monoclonal antibodies Many
From: Hudson, P. J.; Souriau, C. Nature Medicine 2003, 9,

7. 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

8. Cell surface oligosaccharides are determinants of cell recognition
bacterium
virus
cell
toxin
hormone
glycoprotein

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

10. 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

11. Life cycle of the influenza virus
Neuraminidase
cleaves sialic acid
and liberates new
virus
Hemagglutinin
binds sialic acid
to initiate infection SA SA
New viruses
assemble at
membrane
Endocytosis SA SA
Membrane
fusion and
release of
viral particle
Replication
Host cell SA SA

12. Cell Sialic acid analogs block influenza virus infection influenza
“C-Glycoside” of
sialic acid

13. Enzymes catalyze reactions by preferential binding of the transition state vs the ground state
Ea (cat)
Ea (uncat)
Transition state analogs are potent enzyme inhibitors

15. ‡ Design of transition state analog neuraminidase inhibitors
Planarity (sp2)
2,3-Anhydro sialic acid
Ki = 10-6 M
Also inhibits human
neuraminidase

16. Structure-based design of more potent and selective
neuraminidase inhibitors
Binding pocket of
Flu neuraminidase
based on X-ray
structure
Relenza
(Glaxo Smithkline)
Ki = M
Tamiflu
(Hoffman La Roche)
Ki = M

17. 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

18. A hallmark of inflammation is the recruitment of leukocytes from the bloodstream into surrounding tissues
Tissue
Leukocyte
Blood vessel
Activated endothelium

19. The initial attachment of leukocytes to endothelial cells
at sites of inflammation is mediated by the selectins
Leukocyte
L-selectin
P-selectin
E-selectin
Endothelial cell

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

23. Limitations of sLex as a therapeutic agent
• Lack of potency
• Poor pharmacokinetics
• Difficult and expensive synthesis
Possible solutions
• Glycomimetics
• Oligomerization
• Glycoprotein constructs

26. (in clinical development at Texas Biotech.)

27. Limitations of sLex as a therapeutic agent
• Lack of potency
• Poor pharmacokinetics
• Difficult and expensive synthesis
Possible solutions
• Glycomimetics
• Oligomerization
• Glycoprotein constructs

29. Nagy and coworkers

30. Kiessling and coworkers

31. Limitations of sLex as a therapeutic agent
• Lack of potency
• Poor pharmacokinetics
• Difficult and expensive synthesis
Possible solutions
• Glycomimetics
• Oligomerization
• Glycoprotein constructs

32. Approaches to selectin inhibitors inspired by the
discovery of their biological ligands

33. Structure of the biological selectin ligands

34. Determinants of PSGL-1 required for
P-selectin binding

35. 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

36. Leukocyte adhesion to endothelial cells is mediated by L-selectin binding to sulfated sialyl Lewis x
6-Sulfo
sialyl Lewis x
L-Selectin {
Endothelial cell

38. 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

39. Defects in glycolipid degradation lead to lysosomal storage disorders
From: Dwek, R. A., et al. Nature Rev. Drug Disc. 2001, 1,

40. Imino-sugars can block biosynthesis of glycolipid precursors

42. Numerous companies have been founded on glycobiology platforms