BCMB 8130 GlycobiologyGlycosylation of Infectious

Eukaryotes Lecture 23 (4/11/17)

Chris WestBiochemistry & Molecular Biology

Davison Life Sciences B129

Trypanosoma  brucei(artifically colored)

Unicellular parasites have ‘eukaryotic’ glycosylation, with specializations and deletions

Animalglycans:

Parasites utilize generally conserved ‘eukaryotic’ biosynthetic pathways

Parasitecell

MammalianHostcell

Immunecell

InvertebrateHostcell

Parasitecyst

Cell interactions of a parasite

extracellular  milieu

What is the diversity of parasite glycans?

N-­‐glycansO-­‐glycansGPI-­‐anchorsfree  GIPLsanchor-­‐likelipo(phosphono)glycans

other  glycolipidspolysaccharides  – GAG  likepolysaccharide  – neutral

How does glycan diversity influence parasite success?

Evolved  for  self  functionsprotein  networkscarrier  protein

ArmorMimic  host  glycansInvasion  in  distinct  environments  and  of  specialized  targets’Intentional’  inflammation

What is the diversity of glycan receptors (parasite or host)?

Parasite:Protein-­‐glycanglycan-­‐glycanHost  cell:  galectins,  siglecsImmune  cell:Innate  immune  – C-­‐type  lectins:          e.g.,  dectins,  DC-­‐SIGN,  interlectin

Acquired  immune  – vaccines?

Acanthamoeba

Phytophthora

Eukaryotic  phylogeny

Type  of  disease Estimated  human  infectionsEstimated  deaths  per  year  (World  Health  

Report  2000)Parasitic  helminths

Roundworm  (Ascaris) 531  million 3,000

Schistosomiasis 200  million 14,000

Hookworms  (Necator/Ancylostoma) 194  million 7,000

Whipworm  (Trichuris) 212  million 2,000

Filarial  worms 657  million 20,000–50,000

Pinworms  or  threadworms  (Enterobiusvermicularis)

200  million rare

Parasitic  protozoans

Malaria 300–500  million 1–3  million

Leishmaniasis 12  million 57,000

Onchoceriasis  (river  blindness) 18  million 270,000  (blinded)

African  trypanosomiasis  (sleeping  sickness)

450,000 66,000

South  American  trypanosomiasis  (Chagas’      disease)

18  million 50,000

TABLE  40.1Worldwide distribution of some major parasitic diseasesThe  figures  show  the  total  number  of  infections  worldwide  (some  individuals  may  have  more  than  one  infection)  and  the  number  of  infection-­related  deaths  per  year.

Essentials  of  Glycobiology.  2nd  edition.Varki A,  Cummings  RD,  Esko JD,  et  al.,  editors.Cold  Spring  Harbor  (NY):  Cold  Spring  Harbor  Laboratory  Press;  2009.

Parasite CommentsAmoeba  infecting  humansEntamoeba  histolytica causes  amebic  dysentery;  can  cause  liver  

abscessesIntestinal  and  genital  flagellatesGiardia  lamblia causes  diarrhea;  one  of  the  most  common  

parasites  in  North  AmericaTrichomonas  vaginalis causes  inflammation  of  reproductive  organs;  

very  commonHemoflagellatesLeishmania  donovani causes  visceral  leishmaniasis  (kala-­‐azar);  

hepatosplenomegalyL.  mexicana causes  fulminating,  cutaneous  ulcersL.  major causes  cutaneous  ulcersTrypanosoma  brucei sp. causes  sleeping  sickness  in  humans  and  

nagana  in  cattle  (African  trypanosomiasis)

T.  cruzi causes  Chagas’  disease  (South  American  trypanosomiasis)

Gregarines,  coccidia,  and  related  organismsPlasmodium  falciparum major  cause  of  human  malariaP.  vivax,  P.  ovale,  P.  malariae also  cause  human  malaria

Causes  of  opportunistic  infections  in  immunodeficiency  statesToxoplasma  gondii causes  muscle  painPneumocystis  carinii causes  interstitial  cell  pneumoniaCryptosporidium  parvum intracellular  parasite  of  intestinal  cells  that  

causes  diarrhea

TABLE  40.2Some  of  the  major  parasitic  protozoans  of  humans

Toxoplasma gondii, agent of human toxoplasmosis

Toxoplasma proliferation and differentiation

[adapted  from  Sullivan  and  others,  Euk Cell  12:161]

Tachyzoites

Toxoplasma lytic cycle

Stress

Imm

uno-

comprom

ised

Bradyzoite cysts

transmission  EM

phase  contrast  LM

Apicomplexans: Plasmodium spp. (malaria), Toxoplasma gondii (toxoplasmosis), Cryptosporidium (diarrhea)

N-­‐glycans:  low  frequency  of  N-­‐sequonstruncated  Man5 precursor  with  Glc3 terminus  in  T.  gondiiLimited  processing  retaining  high-­‐Man  characterPlasmodium:  GlcNAc1-­‐2-­‐Asn

O-­‐glycans:Minimal  mucin-­‐type  with  αGalNAc reducing  end,  mostly  Tn?  (not  Plasmodium)Glcβ1,3Fucα– disaccharide  on  TSRs  (T.  gondii  &  Plasmodium)C-­‐man  on  WW-­‐motif  of  TSRs  (T.  gondii  &  Plasmodium)

Nuclear:  Cytoplasmic  O-­‐Fuc  formed  by  OGT-­‐like  Spy  in  nucleus  (T.  gondii,  Cryptococcus)Nucleocytoplasmic:  Hyp-­‐linked  complex  O-­‐glycan  (T.  gondii)

GPI-­‐anchors:  Glcα1-­‐4GalNAcβ– side  chain  from  canonical  Man3GlcNH2Inositol  core

starch,  amylopectin: (4Glcα1-­‐)n,  with  α1-­‐6  branches

GalNAc-­‐rich  polysaccharide  (cell  wall):  poorly  characterized

Variations in N-glycosylation

Mainly  due  to  secondary  gene  losses

Association of N-glycans with quality control and ERAD in the rER

Toxoplasma has  no  UGGT  (Parodi enzyme)

Too many hexoses?

Authentic Toxoplasma glycopeptides

Novel side chain on Toxoplasma GPI anchor

Canonical  GPI  anchor

Applications of chemically synthesized GPI anchor

Structure-based discovery of conserved C-Man and Glc-Fuc-Thr on TSP domains

PhyA Gnt1 PgtA-N PgtA-C

Skp1 HOSkp1

OSkp1

AgtA

Dictyostelium glycan: Galα1-3Galα1-3Fucα1-2Galβ1-3GlcNAcα1-4(trans)-O-Pro143-Skp1

AgtA

OSkp1

OSkp1OSkp1OSkp1

OSkp1OSkp1Glt1

Gat1

Toxoplasma-specificGlcNAc Gal Fuc Glc

Dictyostelium-specific

Complex cytoplasmic glycosylation pathway devoted to a hydroxyproline residue on Skp1, an E3 ubiquitin ligase subunit

AAL  binding  to  Western  blots  of  Toxoplasma proteins  is  lost  in  KO  of  TgSPY.  β-­elimination  removes  the  majority  of  O-­linked  fucose.

Increasing  amount  of  protein  loaded.

β-­‐elimination

RH RHTgSPY KO

80

245

50

TgSPY KOFucα-Ser/Thrmonosaccharide modification

AAL  binding  to  nuclei  of  Toxoplasma is  lost  in  a  stable  knock  out  of  an  ortholog of  Arabidopsis SPINDLY  (TgSPY).  

Nuclear localization of O-Fuc

Olszewski et  al.  BBA  (2010)  1673:29

Phylogenetic relationship of Spy (O-FucT) to Sec (O-GlcNAc)

Glycan Class ToxoDB ID Gene Name Description CAZy Config Pred. localization Lourido's fitness phenotype StatusN -linked lipid-linked precursor:

TGGT1_244520 alg7 UDP-GlcNAc GlcNAc-P-T cyto -5.05TGGT1_207070 alg14 UDP-GlcNAc β4GlcNAcT GT1 Inverting cyto -2.63TGGT1_230590 alg1 GDP-Man β4ManT GT33 Inverting cyto -2.51 no mutantsTGGT1_227790 alg2 GDP-Man α3/6ManT GT4 retaining cyto -1.06TGGT1_246982 alg11 GDP-Man α2ManT GT4 retaining cyto -2.7TGGT1_262030 alg6? DPG α3GlcT1 GT57 Inverting secr -1.94 mutantsTGGT1_314730 alg8? DPG α3GlcT2 GT57 Inverting secr -0.97TGGT1_263690 alg10 DPG α2GlcT1 GT59 Inverting secr -0.84

protein-associatedi:TGGT1_231430 stt3 Putative oligosaccharyl transferase GT66 Inverting secr -3.45

GPI-anchor precursor TGGT1_241860 pigA PI α6GlcNAcT catalytic GT4 retaining cyto -5.14TGGT1_310100 pigM DPM α4ManT catalytic GT50 inverting secr -4.66TGGT1_270220 pigV DPM α6ManT, smp3 GT76 inverting secr -3.05TGGT1_321660 pigB DPM α2ManT GT22 inverting secr -3.27TGGT1_266310? βGalNAcT branch, or TGGT1_207750? GT13/17 inverting secr -1.89, -0.47 ongoingTGGT1_266320? αGlcT branch terminus GT32 retaining secr -0.99

O -linked initial (secretory) TGGT1_318730 ppαGalNAcT3 GT27 retaining secr -0.03TGGT1_256080 pp-αGalNAcT1 GT27 retaining secr 1.37TGGT1_258770 ppαGalNAcT12 GT27 retaining secr -0.07TGGT1_278518 pp-αGalNAcT5 GT27 retaining secr -1.14TGGT1_259530 pp-αGalNAcT GT27 retaining secr 1.15TGGT1_273550 POFUT2-like, GDP-Fuc O-FucT GT65 inverting secr -0.34 ongoingTGGT1_238040A LPS-modifying-like, or pp Glc/XylT GT90 inverting secr -0.53TGME49_080400 C-αManT GT98 inverting secr -2.37

Potential peripheralTGGT1_239752 Core1β3GalT-like, Fringe-like GT31 inverting secr -1.36 mutants

Polysaccharide (secretory)TGGT1_278110 3βglucan synthase component GT48 inverting cyto 0.86

O -linked (cytoplasmic)TGGT1_315885 gnt1 Skp1 pp-Hyp αGlcNAcT GT60 retaining cyto -0.58 mutantsTGGT1_260650 pgtA Skp1  βGalT/αFucT GT2/GT74 inv/ret cyto -4.15TGGT1_205060 Skp1  αGlcT, GT32a GT32 retaining cyto 0.96TGGT1_310400 Skp1  αGalT, glycogenin-like, GT8a GT8 retaining cyto 2.45 mutantsTGGT1_273500 ogt Spy-type O-linked βGlcNAcT GT41 inverting cyto -0.11 ongoingTGGT1_288390 β3GlcNAcT-like GT2 inverting cyto -1.93TGGT1_462962 β4GalT-like? GT7C inverting cyto -0.95TGGT1_217692 β4GlcAT-like GT47 retaining cyto 0.45

Cytoplasmic polysaccharideTGGT1_222800 Putative starch synthase- starch GT5/GT1 inverting cyto -0.7TGGT1_310670 α4glucan phosphorylase GT35 retaining cyto 1.01TGGT1_209960 α4glucan branching enzyme GT1/GT4 cyto -0.75TGGT1_246982 UDP-GlycosylT/glycogen phosphorylase GT1 inverting cyto -2.7

Small molecule conjugatesTGGT1_297720 otsA α,α-trehalose-phosphate synthase GT20 retaining cyto -2.89

Donor formationTGGT1_216540 alg5 Dolichyl-phosphate βGlc synthase GT2 inverting cyto -3.36TGGT1_277970 dpm1 Dolichyl-phosphate αMan synthase GT2 inverting cyto -4.37TGGT1_218200 UDP-sugar pyrophosphorylase cyto -0.92TGGT1_264780 UDP-GlcNAc pyrophosphorylase cyto -5.22TGGT1_257960 GDP-Man pyrophosphorylase cyto -4.6TGGT1_216260 TTP:Glc-1-phosphate thymidylyltransferase cyto -4.15TGGT1_274190 TTP:Glc-1-phosphate thymidylyltransferase cyto -5.07TGGT1_272640 Cytidylytransferase cyto 0.23TGGT1_225880 galE UDP-Glc 4-epimerase cyto 1.73TGGT1_229780 galactokinase, GK cyto -2.18TGGT1_286220 GDP-Man epimerase/reductase cyto 0.53TGGT1_238940 GDP-Man dehydratase cyto -0.53TGGT1_243600 GNA, GlcNH2-6-PO4 N-acetyltransferase cyto 1.41TGGT1_260140 PMI cyto -4.96TGGT1_239710 PMM cyto -2.66TGGT1_231350 GFAT, glutamine fructose-6-PO4 isomerase cyto -4.57TGGT1_264650 PAGM, phosphoacetylglucosamine mutase cyto -2.94TGGT1_265450 hexokinase cyto -1.37TGGT1_318580 PGM2, phosphoglycomutase 2 cyto 0.25TGGT1_285980A PGM1, phosphoglycomutase 1 cyto 1.18TGGT1_285980B PGM1, phosphoglycomutase 1 cyto 1.5

Xporter, sugar nucleotideTgME49_067380 nst1 UDP-GalNAc/GlcNAc transporter xmemb 0.97TgME49_054580 pred. sugar nucleotide transporter xmemb -4.9TgME49_067730 pred. sugar nucleotide transporter xmemb 1.23

Opportunities for biosynthetic and functional studies: predicted glycogenome of Toxoplasma gondii

Genome  wide  CRISPR/Cas9  screen  for  fitness  reveals  many  glycgenes are  essential  for  growth  in  mammalian  fibroblast  culture

Plasmodium glycome is further reduced

Parasite Stage Protein SpecificityPlasmodium  falciparum

merozoite EBA-­‐175 Neu5Acα2-­‐3Gal/glycophorin  A

merozoite EBA-­‐140 sialic  acid/glyco  phorin  B?

merozoite EBA-­‐180 sialic  acidsporozoite circumsporozoite  

proteinheparan sulfate

Trypanosoma  cruzi trypomastigote trans-­‐sialidase Neu5Acα2-­‐3Gal

trypomastigote penetrin heparan sulfateEntamoeba  histolytica

trophozoite Gal/GalNAc lectin Gal/GalNAc

Entamoeba  invadens

cyst cyst  wall  protein  (Jacob  lectin)

chitin

Giardia  lamblia trophozoite taglin  (α-­‐1  giardin) Man-­‐6-­‐phosphateheparan sulfate

Cryptosporidium  parvum

sporozoite Gal/GalNAc lectin Gal/GalNAc

sporozoite Cpa135  protein ?Acanthamoeba  keratitis

trophozoite 136-­‐kD  mannose-­‐binding  protein

mannose

Toxocara  canis larval TES-­‐32 ?Haemonchus  contortus

gut-­‐localized galectin β-­‐galactosides

TABLE 40.4Some major parasites and their glycan-recognizing proteins

Life cycle of Trypanosoma cruzi

trypomastigote amastigotes

Cellular invasion of a trypomastigote

Examples of cell surface glycoprotein activities

Trypanosomatids: Leishmania spp., T. cruzi, T. brucei, and others

N-­‐glycans:Non-­‐glucosylated precursors  but  there  is  the  Parodi enzymeTwo  Stt3  types  that  transfer  different  precursors  (Man9GlcNAc2,  and  Man5GlcNAc2)Ill-­‐defined  processing  to  ‘complex’  forms  in  T.  cruzi trypomastigotes:  peripheral  sialic  

acid,  sulphate,  fucose,  Galα1,3Gal–T.  brucei  processes  to  conventional  complex  with  extensive  branched  poly-­‐LacNAc arms

O-­‐glycans:  Complete  set  of  mucin-­‐type  of  up  to  5-­‐mers  built  on  αGlcNAc  rather  than  αGalNAc,  by  a  homologous  polypeptide  HexNAcT.  Not  observed  in  T.  brucei,  but  genes  are.

Complex  phosphodiester-­‐linked  glycans  in  T.  cruzi gp72

Nuclear:  Base  J,  Glc-­‐hydroxymethyluracil in  DNA

GPI-­‐anchors:  novel  substituents

GIPLS:  related  to  anchors

Lipophosphonoglycans: prominent  in  Leishmania  spp.

Cell surface glycosylation in T. cruzi

‘GIPLs’

The cell surface glycome of the African trypanosome, Trypanosoma brucei, an extracellular parasite, varies from the South American trypanosome, T. cruzi.

Further variations in the trypanosomatid LeishmaniaMore  glycolipids  than  glycoproteins

Note  absence  of  Glc3 extension.  But  T.  cruzi has  the  Parodi enzymeSome  α-­‐mannosidase  processing  after  transfer  to  protein  in  epimastigotesEvidence  for  complex  N-­‐glycans  in  trypomastigotes – poorly  characterized

NETNES: an ’extreme’ T. cruzi glycoprotein

N-glycan can substitute for a protein α-helix in VSG isoforms in T. brucei

ex  Taylor  &  Drickamer,  2e

A. Life Cycle and cell surface glycocalyx

Thrα

β4

Thrα

β4α3

Thrα

β4

β6

GlcNAc Galp Galf Sialicacid

Thrα

β2 β4

β6

Thrα

β4α3

B. Selected O-glycan structures

f

f

catalytic domainsignal

anchor

NH2- -COOH

TcOGNT1

TcOGNT2

TcOGNTL

100 aastem

Tcα3GalT

C. Glycosyltransferases

Diversity and strain-specific variation in T. cruzi O-glycans

Novel mechanism of sialylation involves a parasite trans-sialidase

GIPLs from T. cruzi epimastigotes

Developmental regulation of GPI-anchors from T. cruzi

Epimastigotes metacyclics trypomastigotes

GJ  Boons  et  al

Complex, phosphodiester-linked glycan on T. Cruzi GP72Located  in  epimastigote flagellum  adhesion  zone

UDP-α-Galf

UDP-α-Galp

UDP-Glc epimerase [essential] (GalE; TcCLB.506811.190)

predicted UDP-Galf transporter(s)

Galf-(N-glycan)-protein

UDP-α-Galf

βGalf-transferase(s)

Galf-(O-glycan)-protein (not CL or Y)

βGalf-transferase(s)

Galf-(GPI-anchor)-protein

βGalf-transferase(s)

Galf-(free GIPLs)

βGalf-transferase(s)

Candidates (~65):

Candidates:TcCLB.504057.120TcCLB.510611.20TcCLB.511737.70TcCLB.506753.60TcCLB.507089.40TcCLB.506579.80TcCLB.506691.22TcCLB.511353.30

Golgi lumen

UDP-Galp mutase(TcCLB.507993.160)

UDP-α-Glcp

Origin of βGalf in T. cruziglycans

Glycan Class TritrypDB ID 2nd allele Gene name Description CAZy Config Pred. localization StatusN -linked lipid-linked precursor:

TcCLB.510283.140 TcCLB.503823.104 alg7 UDP-GlcNAc GlcNAc-P-T cytoTcCLB.504071.90 alg14 UDP-GlcNAc β4GlcNAcT GT1 Inverting cytoTcCLB.508891.10 TcCLB.504215.20 alg1 GDP-Man β4ManT GT33 Inverting cyto targetTcCLB.506559.420 alg2 GDP-Man α3/6ManT GT4 retaining cytoTcCLB.506885.10 alg11 GDP-Man α2ManT GT4 retaining cyto targetTcCLB.510187.404 alg3 DPM α3ManT GT58 Inverting secrTcCLB.509429.220 TcCLB.507603.150 alg9 DPM α2ManT GT22 Inverting secr targetTcCLB.511621.60 TcCLB.509317.50 alg12 DPM α6ManT GT22 Inverting secr

protein-associatedi:TcCLB.505163.80 TcCLB.427355.10 stt3 oligosaccharyltransferase, cat. GT66 inverting secr targetTcCLB.510329.130 ggt UDP-Glc:Man αGlcT GT24 retaining secr targetTcCLB.509233.40 TcCLB.509437.80 α3/4FucT GT10 Inverting secrTcCLB.506893.90 TcCLB.508501.240 α2/3FucT GT11 Inverting secrnumerous ManI, ER-Man, EDEMs GH47 secrTcCLB_506195.120 TcCLB_506407.10 ManII,ManIIx GH38 secr

GPI-anchor precursor Tc00.1047053509215.16 TcCLB.510259.18 GPI3 pigA, PI α6GlcNAcT catalytic GT4 retaining cytoTcCLB.503909.100 TcCLB.511507.50 GPI14 pigM, DPM α4ManT catalytic GT50 inverting secrTcCLB.503521.89 GPI18 pigV, DPM α6ManT GT76 inverting secrTcCLB.503527.40 TcCLB.510299.50 GPI10 pigB, DPM α2ManT GT22 inverting secr

O -linked initial (secretory) TcCLB.511309.70 TcCLB.511759.30 TcOGNT2 pp-Thr αGlcNAcT GT60 retaining secr targetTcCLB.503511.10 TcCLB.508741.340 TcOGNT1 pp-Thr αGlcNAcT GT60 retaining secr targetTcCLB.503509.10 TcCLB.508741.360 TcOGNTL pp-Thr αGlcNAcT-like GT60 retaining secr targetTcCLB.507275.20 GlcNAc-P-T-like secr

Potential peripheralnumerous βGalf T GT40 inverting secrnumerous β3GalT,β3GlcNAcT,β2GlcNAcT GT67 inverting secrTcCLB.508461.84 α3GalT-like GT77 retaining secrTcCLB.508515.50 TcCLB.508641.160 ? GT8 retaining secrTcCLB.508677.150 TcCLB.503401.40 ? GT8 retaining secrTcCLB.508027.60 TcCLB.506633.109 ? GT8 retaining secrTcCLB.510719.220 TcCLB.509745.20 ? GT4 retaining secrTcCLB.508737.80 TcCLB.509125.10 ? GT4 retaining secrTcCLB.506627.90 EOGT, XylT, AraT? GT61 inverting secrTcCLB.510861.110 EOGT, XylT, AraT? GT61 inverting secrTcCLB.506797.40 TcCLB.511907.10 EOGT, XylT, AraT? GT61 inverting secrTcCLB.510275.90 TcCLB.510275.10 α4GlcNAcT-like GT64 retaining secr

Polysaccharide (secretory)

O -linked (cytoplasmic)TcCLB.503675.10 LPS, HyL GlcT-like GT25 inverting cytoTcCLB.506337.40 LPS, HyL GlcT-like GT25 inverting cytoTcCLB.506733.70 LPS, HyL GlcT-like GT25 inverting cytoTcCLB.511857.30 LPS, HyL GlcT-like GT25 inverting cytoTcCLB.503747.40 TcCLB.510187.10 Base J βGlcT ? inverting nuclTcCLB.510279.240 α4GlcNAcT-like GT64 retaining cyto

Cytoplasmic polysaccharide

Small molecule conjugatesTcCLB.508857.40 TcCLB.508089.20 UDP-GlcT or GlcUAT GT1 inverting secrTcCLB.510761.76 UDP-GlcT or GlcUAT GT1 inverting secr

Donor formationTcCLB.508169.60 TcCLB.506581.10 Dpm1 Dol-P-Man synthase GT2 inverting cytoTcCLB.511761.10 UDP-Glc pyrophosphorylase cytoTcCLB.504153.180 UDP-Glc pyrophosphorylase cytoTcCLB.503589.10 TcCLB.510947.10 GDP-Man pyrophosphorylase cyto targetTcCLB.503881.20 GDPMan 4,6 dehydratase cyto targetTcCLB.506359.60 TcCLB.503521.50 UTP:Glc-1-P uridylT cytoTcCLB.506811.190 GalE UDP-Gal epimerase cytoTcCLB.507993.160 Glf UDP-Galp mutase cyto targetTcCLB.508465.90 Gal-kinase cyto targetTcCLB.511641.5 put. Fuc-kinase cytoTcCLB.509111.28 TcCLB.508379.10 put. Fuc-kinase cyto targetTcCLB.511717.90 TcCLB.503677.10 Type I phosphomannose isomerase cyto

Xporter, sugar nucleotideTcCLB.504085.60 Sug. Nucl. transporter, putative xmemb targetnumerous predicted UDP-Galf & UDP-GlcNAc transporter xmembnumerous predicted UDP-Galf transporter xmembnumerous predicted UDP-GlcNAc transporter xmemb

Opportunities for biosynthetic and functional studies: predicted glycogenome of Trypanosoma cruzi

Genetic  analysis  challenging  as  some  steps  appear  to  be  encoded  by  large  gene  families

Parasite Stage Protein SpecificityPlasmodium  falciparum

merozoite EBA-­‐175 Neu5Acα2-­‐3Gal/glycophorin  A

merozoite EBA-­‐140 sialic  acid/glyco  phorin  B?

merozoite EBA-­‐180 sialic  acidsporozoite circumsporozoite  

proteinheparan sulfate

Trypanosoma  cruzi trypomastigote trans-­‐sialidase Neu5Acα2-­‐3Gal

trypomastigote penetrin heparan sulfateEntamoeba  histolytica

trophozoite Gal/GalNAc lectin Gal/GalNAc

Entamoeba  invadens

cyst cyst  wall  protein  (Jacob  lectin)

chitin

Giardia  lamblia trophozoite taglin  (α-­‐1  giardin) Man-­‐6-­‐phosphateheparan sulfate

Cryptosporidium  parvum

sporozoite Gal/GalNAc lectin Gal/GalNAc

sporozoite Cpa135  protein ?Acanthamoeba  keratitis

trophozoite 136-­‐kD  mannose-­‐binding  protein

mannose

Toxocara  canis larval TES-­‐32 ?Haemonchus  contortus

gut-­‐localized galectin β-­‐galactosides

TABLE 40.4Some major parasites and their glycan-recognizing proteins

Polysaccharides of parasite cyst walls