Purpose To analyse high-molecular-weight matrix glycoproteins in trabe
cular meshwork, cornea and sclera using SDS/PAGE and immuno- and lecti
n blotting. Method Extracts of normal trabecular meshwork (TM), cornea
and sclera were analysed under reducing conditions on SDS/ PAGE. West
ern blots were stained for total protein, and major high-molecular-wei
ght components were identified by immunoblotting with antibodies to fi
bronectin (FN) and type VI collagen. Lectin blotting with PSA, MPA and
DSA identified some of the glycoprotein glycans. Results FN antibody
bound to the 240 kDa band in TM, cornea and sclera. Type VI collagen a
ntibody bound more strongly to one hand and less so to two other bands
at similar to 200 kDa in normal Till and to a ladder of bands in corn
ea and sclera. PSA and DSA bound at 240, 200 and 140 kDa in TM, cornea
and sclera. MPA bound at 240, 200 and 140 kDa in TM and at 240, 200 a
nd similar to 120 kDA in cornea and sclera. Conclusions FN is a compon
ent of the band at 240 kDA in TM, cornea and sclera. Normal Th I was f
ound to contain relatively more of one of the isoforms of the alpha 3
(VI) chain whilst cornea and sclera contained all the alpha 3 (VI) iso
forms. Complex N-linked bi/tri-antennary glycans were localised in FN
and the alpha 1, alpha 2 and alpha 3 (VI) chains in TM, cornea and scl
era. O-linked glycans (identified by MPA binding) were located in FN a
nd alpha 3 (VI) chains of TM, cornea and sclera.