Endo H Application: Monitoring Protein Trafficking

Endo H (Endo-ß-N-acetylglucosaminidase H) is a 29,000 dalton protein with optimal activity between pH 5 and 6. In contrast to PNGase F, which cleaves all N-linked glycans at the site of attachment to Asparagine (Asn), (with the exception of those with fucose attached to the core GlcNac moieties), Endo H hydrolyses the bond connecting the two GlcNac groups that comprise the chitobiose core (see Figure 1.). In addition, Endo H cleaves high mannose and hybrid glycans, whereas complex glycans (those with more than 4 different sugar types per glycan chain, including the GlcNac groups) are resistant to hydrolysis.

The unique specificty of Endo H and PNGase F can be used to monitor protein trafficking. Basic N-Glycosylation occurs in the endoplasmic reticulum. Proteins in this stage are sensitive to Endo H digestion. If proteins have entered the Golgi body where additional modifications occur to the glycan, they are resistant to Endo H digestion.

The following references illustrate this application: