Keratan sulfate carbohydrate chains

The poly-iV-acetyllactosamine glycans were first discovered as constituents of N-glycans in erythrocytes [36] and teratocarcinoma cells [37], in which they represent a major fraction of the cell surface carbohydrates. In contrast, analysis of whole brain tissue does not indicate the presence of major amounts of poly-77-acetyllactosamine chains [15]. That poly-A -acetyllactosamine glycans do exist in brain tissue is suggested by their accumulation in GMl-gangliosidosis [38]. Small amounts are also present in the form of keratan sulfate as 0-mannose linked chains (see above). 

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