Question

The core glycan moiety of N-linked glycoproteins contains

• A. fifteen mannose units
• B. five N-acetyl glucosamine units
• C. three glucose units
• D. three N-acetyl neuraminic acid units

Hint:

Remember: The core glycan composition is Glc₃Man₉GlcNAc₂.

Answer 1

The Correct Option is C

Step 1: Understanding N-linked Glycoproteins.
N-linked glycoproteins have carbohydrate chains attached to asparagine residues. The core glycan is built on a dolichol phosphate in the endoplasmic reticulum.
Step 2: Composition of Core Glycan.
The common core structure contains three glucose, nine mannose, and two N-acetylglucosamine residues. Among them, the three glucose units form the terminal part crucial for folding quality control.
Step 3: Conclusion.
Thus, the core glycan moiety contains three glucose units.