Chemistry Chat

Proteasome is a protein complex consisting of 19S cap units and a 20S core unit with a molecular weight of about 2000kDa. Proteasome incorporates targeted proteins and degrades them into short peptides or amino acids. The structure of proteasome is the cylindrical 20S core unit in the center and both sides of it bind with a 19S cap unit.

The 19S cap acts to unfold the target proteins for degradation. After unfolding the higher-order structure of the target proteins and incorporating them into the cylindrical 20S core unit, they are degraded into short peptides or amino acids catalyzed by enzymes. This protein degradation process proceeds in three steps as follows: tagging the protein by ubiquitin, incorporation of the tagged proteins into the 19S cap, and enzymatic degradation within the 20S core.