NCIt definition : A naturally-occurring salinosporamide, isolated from the marine actinomycete Salinospora
tropica, with potential antineoplastic activity. Marizomib irreversibly binds to and
inhibits the 20S catalytic core subunit of the proteasome by covalently modifying
its active site threonine residues; inhibition of ubiquitin-proteasome mediated proteolysis
results in an accumulation of poly-ubiquitinated proteins, which may result in the
disruption of cellular processes, cell cycle arrest, the induction of apoptosis, and
the inhibition of tumor growth and angiogenesis. This agent more may more potent and
selective than the proteasome inhibitor bortezomib.;