Preferred Label : Copper Cu 64-GRIP B;
NCIt synonyms : [64Cu]-GRIP B; 64Cu-GRIP B; 64Cu-labeled GRIP B;
NCIt definition : An imagining agent composed of granzyme targeted restricted interaction peptide (RIP)
specific to family member B (GRIP B) and radiolabeled with the radioisotope copper
Cu 64, that can potentially be used to detect granzyme B (GZMB) activity upon positron
emission tomography (PET). RIP consists of three domains, including a) Temporin L,
an antimicrobial peptide (AMP) and membrane binding domain that is coupled to copper-64,
b) a specific GZMB substrate and endoprotease cleavage binding domain, and c) a peptide
masking domain that prevents the AMP from adopting its preferred helical conformation.
Upon administration of copper Cu 64-GRIP B, the protease cleavage binding domain of
RIP is specifically cleaved by extracellular GZMB, and upon cleavage, the AMP changes
conformation and the radiolabeled activated AMP targets and irreversibly binds to
adjacent phospholipid bilayers within any nearby membranes, thereby sequestering the
radioisotope to nearby tumor cells. Upon PET, tissue biodistribution of the radioisotope
can be assessed and the accumulated radioisotope in tissues reflects the proteolytic
activity of secreted GZMB. GZMB secretion and activity is correlated with immune cell
activation and can be enhanced by certain immune checkpoint inhibitors.;
NCI Metathesaurus CUI : CL1906831;
Origin ID : C199470;
UMLS CUI : C5855614;
Semantic type(s)
- concept_is_in_subset
