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Bacterial lectins and infection – from structural glycobiology to antiadhesive strategies e-Learning in Glycobiology and Glycochemistry Lisbonn 8 october 2012 Anne Imberty CERMAV-CNRS Grenoble, France

Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

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Page 1: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

Bacterial lectins and infection – from structural

glycobiology to antiadhesive strategies

e-Learning in Glycobiology and Glycochemistry

Lisbonn

8 october 2012 Anne Imberty

CERMAV-CNRS

Grenoble, France

Page 2: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Lectins

-Ubiquitous- > 500 crystal structures

(www.cermav.cnrs/lectines)

-Multivalency achieved by -Tandem repeat

-Oligomerisation

-Surface presentation

-Affinity and avidity

-Low affinity for monosaccharides

-Avidity for multivalent ligands

Page 3: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Page 4: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

- Lectins : distribution and role in infection

- Structure, specificity, multivalency of lectins

- Lectins as drug targets against infection

Learning objectives

Page 5: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

New Lectin-3D database(http://glyco3d.cermav.cnrs.fr/glyco3d/)

> 1000 entries

Page 6: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Lectins in mammalsQuality control, Cargo-Traffic, Cell-cell recognition, Pathogen opsonisation

Drickamer &Taylor, Trends Biochem. Sci., 1998

Page 7: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Sinularia lochmodes

Lectins(SLL1 to SLL3)

Symbiosis with zooxanthella Symbiodinium

(Koiki et al., Biol. Bull. 2004)

Helix pomatia

Protection of eggsfrom pathogens

AgglutininHPA

.

(Uhlenbruck & Prokop Vox Sang. 1966) (Barondes et al., J. Cell Biol. 1983)

Dictyostelium discoideum

Discoidins(DiscI, DiscII)

Development (Sanchez et al, J. Biol. Chem. 2006)

Lectins in invertebratesSelf / non-self recognition

Page 8: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Lectin in plant and fungiDefense - symbiosis

Schubert et al. PLoS Pathog. 2012

CCL2 from Coprinopsis cinereaGlcNAcβ1,4[Fucα1,3]GlcNAc

Liu et al. Science 2012

LysM domain of chitin receptorfrom Arabidopsis /chitotetraose

Fluorescence microscopy of C.

elegans feeding on E. coli expressing

a dTomato-CCL2 fusion protein

Page 9: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Dendritic cells Fluids

Macrophages

DC-SIGN

SP-DMBP Mannose-

receptor

Soluble lectins Toxins

Adhesins

Bacterial GBPs

Host GBPs

+

+ -

-

Page 10: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Imberty & Varrot, Curr. Opin. Struct. Biol. 2008

Lectin in bacteria and viruses

Page 11: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

Common in freshwater:

“Hot Tub” folliculitis

Acute diffuse otitis externa (swimmer’s ear)

Pseudomonas “hot-foot” syndrome

Most common pathogen isolated from patients hospitalized longer than one week

A major hospital pathogen:

10-15% nosocomial infection world while (mortality rate 40 to 60%)

high endemic potential in intensive care units: 18 %

Pseudomonas aeruginosa

The leading killer of cystic fibrosis patients

0

10

20

30

40

50

60

70

80

90

100

0 - 4 5 - 9 10 - 14 15 - 19 20 - 24 25 - 29 29 - 30 35 ou +

P. aeruginosa

S. aureus méti S

S. aureus méti R

H. influenzae

S. maltophilia

Classes d’âge

% Patients

0

10

20

30

40

50

60

70

80

90

100

0 - 4 5 - 9 10 - 14 15 - 19 20 - 24 25 - 29 29 - 30 35 ou +

P. aeruginosa

S. aureus méti S

S. aureus méti R

H. influenzae

S. maltophilia

Classes d’âge

% Patients

Page 12: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

LecA

LecB

Type IV pili / asialo oligo

Type 1 and type p pili

FliD / Sialyl Lewis X ?

Pseudomonas aeruginosa glyco-strategy

Soluble lectins

Page 13: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Bacterial material

PAO1 PAO1 TnA PAO1 TnB

P. aeruginosa

PAO1 TnAR PAO1 TnBR

Wild type Mutant LecA Mutant LecB

Recomplementation

1 In vitro studies

� Lung epithelial cells (A549)

� Cytotoxicity de P. aeruginosa

2. In vivo studies

� Acute pneumonia experimental model

�P. aeruginosa pathogenicity

- Mortality

- Lung lesion (albumin 125I-albumin)

- Bacterial load in lungs

- Translocation from lungs

BalB/c

Endotracheal instillation

Role of LecA and LecB in P. aeruginosa pathogenicity

(coll. B. Guery & S. de Bentzmann)

Page 14: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

H6 H1610 4

10 5

10 6

10 7

10 8

10 9

1010

PAO1

PAO1 TnA

PAO1 TnB

***

**

Temps après infection

UFC / poumons

Bacterial load in lungs

Inoculum = 5×106 UFC/souris

n = 10/groupe. * p < 0.05, *** p < 0.001 vs PAO1

Chemani et al. (2009) Infect .Immun.

CTR

PAO1

PAO1

TnA

PAO1

TnA R

PAO1

TnB

PAO1

TnB R

0

1

2

3

4

5

125- I-albumine (%)

B

H16

***

*

Pulmonary lesions from P. aeruginosa

Role of LecA and LecB in mice model infection

Strain ∆∆∆∆LecAStrain ∆∆∆∆LecB

Page 15: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

0 1 2 3 4 5 6 70

20

40

60

80

100

PA

PA + Me-αααα-Fuc

PA + Gal-Nac

PA + Me-αααα-Gal

**

Temps (jours après infection)

Survie (%)

Protective effect of monosaccharides on P. aeruginosa

infection

n = 20/groupe. * p < 0.05 vs PAO1

Inoculum = 5××××107 UFCM/mice

�Experimental model of acute pneumoniae in mice

BalB/c

Co-administration endotracheal PA + sugars (15mM)

Survival (days)

Chemani et al. (2009) Infect .Immun.

Page 16: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

- Lectins : distribution and role in infection

- Structure, specificity, multivalency of lectins

- Lectins as drug targets against infection

Learning objectives

-Lectins are ubiquitous and interprete the glycocode

- Many lectins are involved in host-pathogen interactions

- LecA and LecB from Pseudomonas aeruginosa are virulence factors

Page 17: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

Characterisation of lectin/glycan interactions

Glycan arrayCFG

Specificity

Titration calorimetry

(ITC)

Affinity

Thermodynamics

n, Ka, ∆∆∆∆H

Affinity

Kinetics

Kon, Koff

Structure

Surface Plasmon Resonance

(SPR)

CrystallographyModeling

Page 18: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

LecB from P. aeruginosa

PA-IIL / LecB

�114 amino acids / pI 3.88

�Specific for L-fucose / D-mannose

� Affinity in the micromolar range for fucose

� Tetrameric

� Binding properties dependent on divalent cations

Gilboa-Garber,Meth. Enzymol. 1992

� Recombinant in E. coli

� Purified in 1 step on mannose/agarose column

Page 19: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Consortium for Functional Glycomics : http://www.functionalglycomics.org/fg/

“Glycan array”

Covalent link with glass slide functionalized with N-

hydroxylsuccimidine

“Printed array”

� Lectin labelled with fluorophore (or provided with Ab)

�Concentraton from 0,01 to 200 ug/mL

Glycochips : Glycan arrays and printed arrays

Page 20: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

Specificity of P. aeruginosa LecB by glycan array

0

2000

4000

6000

8000

10000

1 20 39 58 77 96 115 134 153 172 191 210 229 248 267 286 305 324 343 362 381 400 419 438 457

RF

U

Chart No

PA-IIL (1ug/mL) Slide#12863 CFG#2058 ALexa488 5/26/10 Hong

ααααFuc1-2Gal

βGal1-3[ααααFuc1-4]GlcNAc

βGal1-4α[α[α[α[Fuc1-3]GlcNAc

Page 21: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

Ϛغ

•Lavoisier and Laplace (1784)

• Measure heat associated with any process

Titration microcalorimetry

Page 22: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

ɐϛ

22

Titration microcalorimetry

aKlnRTG −=°∆

°∆−°∆=°∆ STHG

Free Energy Enthalpy Entropy

Page 23: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

ϛ

n = 0.77

Ka=2.3 106 M-1

Kd=4.1 10-7 M

∆∆∆∆G= -36.3 kJ.mol-1

∆∆∆∆H= -41.1 kJ.mol-1

-T∆∆∆∆S= 4.1 kJ.mol-1

∆∆∆∆G ∆∆∆∆H -T∆∆∆∆S

MeFuc: 0.44 mM

PA-IIL: 55.8 µM

Thermodynamics of LecB/ααααMeFuc interaction

Page 24: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

ϛ

Kd= 0.21 10-6 M

∆∆∆∆G ∆∆∆∆H -T∆∆∆∆S

Lewis a

Kd= 1.02 10-6 M

∆∆∆∆G ∆∆∆∆H -T∆∆∆∆S

Lewis a Lewis x

LecB/Lewis epitope interactions

ITC

OCH2OH

HO

OHOH

O

O

CH2OH

AcHNOH

O

OHHO

CH3

O

OH

Gal

GlcNAc

Fuc

βGal1-3[ααααFuc1-4]GlcNAc

Lewis x

OCH2OH

HO

OHOH

O O

NHAcOH

CH2OH

O

OHHO

CH3

O

OH

Gal

GlcNAc

Fuc

βGal1-4α[α[α[α[Fuc1-3]GlcNAc

Page 25: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

ϛ

Surface Plasmon Resonance

Page 26: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

ϛ

Sugar on the surface

Lectin on the surface

Chip CM5 + Streptavidin + Biot-lectin

Chip NTA + HisTag-lectin

Chip CM5 + Lectin (amine coupling)

CM5 Fc

1Fc2

Fc1Fc1

CM5

NTA

CM5

+

Ni2+

NT

A

CM5

Chip CM5 + Streptavidin + Biot-PAA-Fuc

DetectionRegeneration

Glycan

Glycan

Glycan

???

???

???

EDTA

Page 27: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

)

Lewis a Lewis x

LecB/Lewis epitope interactions

-50

0

50

100

150

-1000 0 1000 2000 3000 4000 5000

Lewis a (RU)

Lewis x (RU)

Kon (Lex): 486 Ms-1

Kon (Lea): 1446 Ms-1

SPR

OCH2OH

HO

OHOH

O

O

CH2OH

AcHNOH

O

OHHO

CH3

O

OH

Gal

GlcNAc

Fuc

OCH2OH

HO

OHOH

O O

NHAcOH

CH2OH

O

OHHO

CH3

O

OH

Gal

GlcNAc

Fuc

βGal1-3[ααααFuc1-4]GlcNAcβGal1-4α[α[α[α[Fuc1-3]GlcNAc

Page 28: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

ϛ

X-ray crystallography

Page 29: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

㦀Ϝ

Mitchell et al (2002)

Nature Struct. Biol.

Page 30: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

O2

O3

O4

C6

Specificity of LecB for fucose

Mitchell et al. & Imberty (2003) Nature Struct. Biol.

Page 31: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

㦀Ϝ

Crystal structure of the LecB/Lewis a complex

KD Lewis a

0.21 µµµµM

.Perret et al. (2005) Biochem. J

KD ααααMeFuc

0.5 µµµµM

ITC

OCH2OH

HO

OHOH

O

O

CH2OH

AcHNOH

O

OHHO

CH3

O

OH

Gal

GlcNAc

Fuc

Page 32: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

묰Ϝ

Lewis X

Crystal structure

NHAc

OH

O

OH

OH

O

OHCH

3

O

O

CH2OH

OH

CH2OHO

OH

OH

3

4

Fuc

Gal

GlcNAc

Lewis a

CH2OH

OH

OH

CH2OHOO

OH

OH

O

OH

OH

O

OHCH

3

O

NHAc3

4

Fuc

Gal

GlcNAc

Model

KD Lewis a

0.21 µµµµM

KD Lewis x

1.02 µµµµM

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쁠Ϝ

LecB / P. aeruginosaLecA / P. aeruginosa

Bc2L-A / B. cenocepacia BambL / B. ambifaria

See Poster P171 / Aymeric Audfray

Relation between topology and function ?

Page 34: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

뮰ϝ

P. aeruginosa

B . cenocepacia

B . ambifaria

Non Sec Le- Non Sec Le+ ALe- A Le+ B Le+ O Le- O Le+

Collab Jacques Le Pendu

Specificity of bacterial lectins towards histo-blood group epitopes

no selectivityspecificity

for Le+

specificity for secretor

Page 35: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

뮰ϝ

- Lectins : distribution and role in infection

- Structure, specificity, multivalency of lectins

- Lectins as drug targets against infection

Learning objectives

-A wide range of tools is available for studying protein/carbohydrate

- Some microbial lectins have high affinity to glycans

- Multivalency and topology play a role in lectin function

-Lectins are ubiquitous and interprete the glycocode

- Many lectins are involved in host-pathogen interactions

- LecA and LecB from Pseudomonas aeruginosa are virulence factors

Page 36: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

뮰ϝ

Antibacterial compounds - strategies

Monovalent MultivalentOligovalent

Imberty et al, Chemistry 2009

Glycomimetics

Aglycone

“polar gate”

Cluster effect

Potent

aggregation

Cluster effect

Chelate effect

Specificity

Page 37: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

솠Ϝ

0

5

10

15

20

25

23

20

22

19

18

21

13

16

14

15

12

Lewis a

fucose

Met-a-L-Fuc

48

49

50

51

52 5 4 1 9

10

55

57

56

59

43

41

30

27

28

26

24

inhibiteurs

potentiel d'inhibition

Série 1 (l-Fuc(α1-4)GlcNac)

Série 2 (Dendrimers of Fuc14GN))

Natural ligands

Série 3 (Isoxazole-(R))

Série 4 (Triazole-(R))

Série 5 (addition at C5)

Série 6 (other additions at C1)

ELLA tests on series of glycomimetics

(coll. René Roy, UQAM)

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뮰ϝ

9.8 8.28.3

KD

3.2 10-7 M

Marotte et al. Imberty & Roy (2007) ChemMedChem

Page 39: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

뮰ϝ

0

5

10

15

20

25

23

20

22

19

18

21

13

16

14

15

12

Lewis a

fucose

Met-a-L-Fuc

48

49

50

51

52 5 4 1 9

10

55

57

56

59

43

41

30

27

28

26

24

inhibiteurs

potentiel d'inhibition

Série 1 (l-Fuc(α1-4)GlcNac)

Série 2 (Dendrimers of Fuc14GN))

Natural ligands

Série 3 (Isoxazole-(R))

Série 4 (Triazole-(R))

Série 5 (addition at C5)

Série 6 (other additions at C1)

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슐Ϝ

OO

N

HO

OO

N

O

OO

NO

ON

O

OHHO

OHO

OHHO

OHO

OHHO

OHO

OHHO

OH

9.8 7.1 7.1 6.8

OO

O

OH

HO

OH

O

OOH

OHHO

N

N

N

O

N

N

N

NO2

N

N

N

O

OH

HO

N

AcHN

OH

N

N

OOH

OHHO

O

OH

HO

OH

9.89.69.8 4.2

KD

7.1 10-7 M

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뮰ϝ

0

5

10

15

20

25

23

20

22

19

18

21

13

16

14

15

12

Lewis a

fucose

Met-a-L-Fuc

48

49

50

51

52 5 4 1 9

10

55

57

56

59

43

41

30

27

28

26

24

inhibiteurs

potentiel d'inhibition

Série 1 (l-Fuc(α1-4)GlcNac)

Série 2 (Dendrimers of Fuc14GN))

Natural ligands

Série 3 (Isoxazole-(R))

Série 4 (Triazole-(R))

Série 5 (addition at C5)

Série 6 (other additions at C1)

Page 42: Bacterial lectins and infection –from structural ... · NHAc HO O HO OH O OH CH 3 O O CH2OH HO O CH2OH OH OH 3 4 Fuc Gal GlcNAc Lewis a CH2OH HO HO O O CH2OH OH OH O HO OH O OH

뮰ϝ

O O OO

HOAcNH

OH

O

O

OH

OHOH

NNN

O

OHAcNH

OH

O

O

HO

OHOH

NN N

O O

C H N O

CP43B

Best multivalent inhibhitors

Kd = 90 10-9 M

∆∆∆∆G = -40.2 kJ.mol-1

∆∆∆∆H = -69.5 kJ.mol-1

-T∆∆∆∆S = 29.3 kJ.mol-1

Kd = 100 10-9 M

∆∆∆∆G = -39.9 kJ.mol-1

∆∆∆∆H = -37.2 kJ.mol-1

-T∆∆∆∆S = -2.7 kJ.mol-1

∆∆∆∆G ∆∆∆∆H -T∆∆∆∆S

∆∆∆∆G ∆∆∆∆H -T∆∆∆∆S

Marotte et al. Imberty & Roy (2007) Org. Biol. Chem.

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쎀ϜLecA LecB

P. aeruginosa lectins inhibitors

Natural 100 µµµµM 210 nM

Monosacch

derivatives 6 µµµµM 290 nM

Oligomers 176 nM 100 nM

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- Lectins : distribution and role in infection

- Structure, specificity, multivalency of lectins

- Lectins as drug targets against infection

Learning objectives

-A wide range of tools is available for studying protein/carbohydrate

- Some microbial lectins have high affinity towards glycans

- Multivalency and topology play a role in lectin function

-Lectins are ubiquitous and interprete the glycocode

- Many lectins are involved in host-pathogen interactions

- LecA and LecB from Pseudomonas aeruginosa are virulence factors

- Glycomimetics are efficient inhibitors of lectin and bactiera adhesion

- Thermodynamic should be considered for designing ligands

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Conclusions and perspectives

- Microbes use our sugars during infection process

- The redundancy of glycan-binding proteins make them difficult to target

- High affinity glycocompounds can be used as anti-infectious agents

- Engineering of bacterial lectins to “neolectins” provide tools with controlled valency and specificity

- Bacterial lectins are excellent tools for research