Which of the following describes the primary characteristic of N-linked glycosylation?

N-linked glycosylation is primarily characterized by the addition of carbohydrate (sugar) moieties to the side chain of asparagine residues in proteins. This post-translational modification plays a crucial role in protein folding, stability, and function, influencing various cellular processes, including cell signaling and cell-cell interaction.

In the process of N-linked glycosylation, a pre-formed oligosaccharide is transferred en bloc to the nitrogen atom of asparagine residues located within a specific consensus sequence. This modification occurs predominantly in the endoplasmic reticulum and Golgi apparatus and is essential for the proper functioning of many glycoproteins.

Understanding the nature of N-linked glycosylation is vital as it affects protein solubility, structural integrity, and interaction with other biomolecules, contributing significantly to the biological activity and half-life of glycoproteins in various tissues.

Therefore, the choice highlighting the addition of sugars to asparagine accurately captures the essence of N-linked glycosylation.