Lectin microarray profiling and relative quantification of glycome associated with proteins of neonatal wt and rd1 mice retinae.

PURPOSE: To compare progressive dynamic, relative quantitative changes in glycans associated with retinal proteins of wild type (wt) and retinal degeneration 1 (rd1) mice during neonatal development and degeneration of retinae. METHODS: Proteins extracted from retinae of postnatal day 2 (PN2), PN7, PN14 wt and rd1 mice were labeled with Cy3-fluorescent dye. Glycome of these proteins was quantified relatively by lectin microarray technique. Net fluorescence emitted by individual complexes formed between forty five lectins and Cy3-labeled proteins was measured by evanescent-field-fluorescence-assisted microarray reader. RESULTS: GlcNAcβ1-oligomer and high-mannose/Manα1-6Man were major glycans associated with the proteins of PN2, PN7, PN14 wt and rd1 mice retinae. Gal/GalNAc/Man3-core-bi-/tri-antennary-complex; Sia2-3Galβ1-4GlcNAc and high-mannose glycans were mainly conjugated to proteins from PN7 rd1 and PN14 wt retinae, respectively. With increasing neonatal age, mannosylated, GlcNAcβ, and sialylated (minor component) glycans were increased and fucosylated GlcNAc/Galβ glycans were decreased significantly in wt retinal proteins. This trend was less evident in PN14 rd1 retinal proteins. Mouse retina was almost devoid of Siaα2-6 (except WGA bound Sia), Fucα1-2 and Gal/GalNAc containing glycans. STL reacting GlcNAc oligomers were high in PN2 rd1 retinae. CONCLUSIONS: Quantitative dynamic, relative variation in high-mannose and GlcNAc glycans, Siaα2-3Galβ1-4GlcNAc associated with proteins from PN2, PN7, PN14 wt and rd1 mice retinae suggested that these glycans participate in retinal development and degeneration and may be used as markers for retinal electrophysiological integrity during transplantation/therapy studies; Siaα2-3Galβ1-4GlcNAc specific Agrocybe cylindracea lectin and other lectins may be used to enrich/purify retinal ribbon synapse glycoproteins and rhodopsin. Further investigations are required.