Nglykosylácia

Glycosylation is a fundamental post-translational modification where carbohydrates, also known as glycans, are enzymatically attached to other molecules, most commonly proteins and lipids. This process plays a crucial role in a vast array of biological functions, influencing protein folding, stability, solubility, and trafficking. Furthermore, glycans are critical for cell-cell recognition, immune responses, and the development of complex organisms.

There are several major types of glycosylation, distinguished by the linkage between the glycan and the acceptor molecule. N-linked glycosylation occurs when the glycan is attached to the nitrogen atom of an asparagine residue within a specific consensus sequence. O-linked glycosylation, in contrast, involves the attachment of the glycan to the oxygen atom of a serine or threonine residue. Other forms include C-linked glycosylation, S-glycosylation, and P-glycosylation, each involving different atoms and amino acid residues.

The enzymatic machinery responsible for glycosylation is complex, involving a variety of glycosyltransferases and glycosidases. These enzymes are often located within the endoplasmic reticulum and Golgi apparatus in eukaryotic cells, where much of protein glycosylation takes place. The precise structure of the attached glycan can vary significantly, leading to a diverse "glycome" that reflects the cell's physiological state and environment. Aberrant glycosylation is implicated in numerous diseases, including cancer and inflammatory disorders, highlighting its importance in health and disease.