changes in protein profiles in bortezomib applied multiple myeloma ...

The β-1, β-2 and β-5 subunits contain the post-glutamyl peptidyl hydrolytic-like,
tryptic-like, and chymotryptic-like proteolytic activities of the 26S proteasome,
respectively (Groll et al., 1997) (Figure 1.9).
Figure 1.9. Cross Section of β Ring
(Source: Adams and Kauffman, 2004; Landis-Piwowar et al., 2006; Roodman, 2009)
Proteins entering the 20S catalytic core are degraded in a progressive manner,
resulting in the release of oligopeptides composing of three to twenty two amino acids
in length (Goldberg et al., 1997; Hershko and Ciechanover, 1998; DeMartino and
Slaughter, 1999; Delcros et al., 2003).
1.2.7.3. Ubiquitin-Proteasome Pathway (UPP)
The degradations process is chiefly mediated by the ubiquitin–proteasome
pathway (UPP). The binding of ubiquitin to the target proteins from its ε-amine of
lysine residues involves a series of ATP-dependent enzymatic steps by E1 (ubiquitin-
activating), E2 (ubiquitin-conjugating) and E3 (ubiquitin-ligating) enzymes. This
combination forms the poly-ubiquitinated protein which serves as substrate for the
destruction of targeted protein by the proteasome (Glickman and Ciechanover, 2002)
(Figure 1.10).
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