Table 1. Representative Structures of Known GPI Anchors (4,6,13,16,18–24)^a.

protein	R1	R2	R3	R4	R5	R6	X
rat brain Thy-1	±Manα1−2	OH	PEtN	±GalNAcβ1−4	OH	OH	alkylacyl-glycerol
human erythrocyte AChE	OH	±PEtN	PEtN	OH	OH	palmitate	alkylacyl-glycerol
hamster brain scrapie prion protein	±Manα1−2	OH	PEtN	(±NANA)- (±Gal)-GalNAcβ1−4	OH	OH	nd
human urine CD59	±Manα1−2	OH	PEtN	±GalNAcβ1−4	OH	palmitate	nd
mouse skeletal muscle NCAM	±Manα1−2	nd	PEtN	±GalNAcβ1−4	OH	OH	nd
bovine liver 5′-nucleotidase	±Manα1−2	±PEtN	PEtN	±HexNAc	OH	OH	nd
human placental APase	OH	±PEtN	PEtN	OH	OH	OH	alkylacyl-glycerol
human CD52	±Manα1−2	±PEtN	PEtN	OH	OH	palmitate	diacyl-glycerol
pig kidney membrane dipeptidase	OH	±PEtN	PEtN	(±Galβ1−3)GalNAcβ1−4 or (±NANA) - GalNAcβ1−4	OH	OH	diacyl-glycerol
human kidney membrane dipeptidase	±Manα1−2	nd	PEtN	(±Galβ1−3)GalNAcβ1−4	OH	OH	nd
T. brucei VSG	OH	OH	OH	±Galα1−2(Galα1−2Galα1−6)Galα1−3	OH	OH	dimyristyl-glycerol
T. cruzi 1G7	±Manα1−2	OH	OH	OH	OH	OH	alkylacyl-glycerol
T. cruzi NETNES	±Manα1−2	OH	OH	OH	PEtN	OH	alkylacyl-glycerol
L. major gp63	OH	OH	OH	OH	OH	OH	alkylacyl-glycerol
S. cerevisiae gp125	±Manα1−2Manα1−2 or Manα1−3Manα1−2	OH	OH	OH	OH	OH	diacyl-glycerol
A. fumigatus PhoAp	±Manα1−3Manα1−2	OH	OH	OH	OH	OH	ceramide
P. communis arabinogalactan proteins	OH	OH	OH	±GalNAcβ1−4	OH	OH	ceramide
D. Discoideum PsA	±Manα1−2	nd	nd	OH	OH	OH	ceramide

^aVarious side chain modifications of carbohydrates, phosphoethanolamine, and/or palmitate (R₁−R₆) are indicated. In some proteins, certain side chains may only be present in a proportion of GPI anchors (indicated by ±). OH indicates that no side chain is known to be present; nd indicates that the side chain or lipid moiety has not been determined. X is the lipid moiety, Man is mannose, Gal is galactose, GalNAc is N-acetylgalactosamine, NANA is sialic acid, HexNAc is N-acetylhexosamine, and PEtN is phosphoethanolamine.