M6P is converted to fructose 6-phosphate by mannose phosphate isomerase. Chemically, guar gum is an exo-polysaccharide composed of the sugars galactose and mannose. This endosperm consists of a large polysaccharide of galactose and mannose. This acidic environment causes dissociation of the lysosomal enzymes from the mannose 6-phosphate receptors. In plants, this is accomplished through the conversion of mannose or galactose to ascorbic acid. Mutation of any of these residues results in the loss of mannose 6-phosphate binding. This enzyme participates in pentose and glucuronate interconversions and fructose and mannose metabolism. Several congenital disorders of glycosylation are associated with mutations in enzymes involved in mannose metabolism. This enzyme participates in fructose and mannose metabolism. Specifically, mannose binding triggers recruitment of MBL-associated serine proteases (MASPs). Xylose, fucose, mannose, and GlcNAc phosphoserine glycans have been reported in the literature. "Cis" cisterna are associated with the removal of mannose residues. Assembly then continues within the endoplasmic reticulum, with the addition of four more mannose residues. Removal of mannose residues and addition of N-acetylglucosamine occur in medial cisternae. Individually, the CRDs bind mannose with only weak affinity.