2. Glycosylation of proteins
•Glycosylation mainly refers to the
enzymatic process that attaches glycans
to proteins, or other organic molecules.
•This enzymatic process produces one of
the fundamental biopolymers found in
cells.
•Glycosylation is a form of co-
translational and post-translational
modification.
3.
4.
5.
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7.
8.
9.
10.
11.
12. Types of Glycosylation
1. The N-linked glycosylation:
1. Process occurs in eukaryotes in the lumen of
the ER
2. N-linked glycans attached to nitrogen of
asparagine or arginine side-chains
2. O-linked glycosylation:
1. Process occurs in eukaryotes in the GA
2. O-linked glycans attached to the hydroxyl
oxygen of serine, threonine, tyrosine,
hydroxylysine or hydroxyproline side chain
13.
14.
15. 3. Phosphoserine glycosylation:
1. Phosphoglycans linked through the phosphate of
phosphoserine
2. Glycans binds to serine via phosphodiester bond
4. C-mannosylation:
1. Rare form of glycosylation
2. Sugar is added to carbon on a tryptophan side chain
3. Mannose binds to the indole ring of tryptophane
5. Glypiation:
1. Glycan core links a phospholipid and a protein