Use of a HEHEHE Purification Tag Instead of a Hexahistidine Tag Improves Biodistribution of Affibody Molecules Site-Specifically Labeled with Tc-99m, In-111 and I-125
2011 (English)In: Journal of Medicinal Chemistry, ISSN 0022-2623, E-ISSN 1520-4804, Vol. 54, no 11, 3817-3826 p.Article in journal (Refereed) Published
Affibody molecules are a class of small (similar to 7 kDa) robust scaffold proteins suitable for radionuclide molecular imaging in vivo. The attachment of a hexahistidine (His(6))-tag to the Affibody molecule allows facile purification by immobilized metal ion affinity chromatography (IMAC) but leads to high accumulation of radioactivity in the liver. Earlier, we have demonstrated that replacement of the His(6)- tag with the negatively charged histidine-glutamate-histidine-glutamate-histidine-glutamate (HEHEHE)-tag permits purification of Affibody molecules by IMAC, enables labeling with [Tc-99m(CO)(3)](+), and provides low hepatic accumulation of radioactivity. In this study, we compared the biodistribution of cysteine-containing Affibody molecules site-specifically labeled with In-111, Tc-99m, and I-125 at the C-terminus, having a His(6)-tag at the N- or C-terminus or a HEHEHE-tag at the N-terminus. We show that the use of a HEHEHE-tag provides appreciable reduction of hepatic radioactivity, especially for radiometal labels. We hope that this information can also be useful for development of other scaffold protein-based imaging agents.
Place, publisher, year, edition, pages
2011. Vol. 54, no 11, 3817-3826 p.
ANTI-HER2 AFFIBODY, HER2 EXPRESSION, HER2-EXPRESSING TUMORS, RECOMBINANT PROTEINS, MALIGNANT-TUMORS, PEPTIDE, AFFINITY, TECHNETIUM, SCAFFOLD, THERAPY
Other Basic Medicine
IdentifiersURN: urn:nbn:se:kth:diva-34657DOI: 10.1021/jm200065eISI: 000291082500010ScopusID: 2-s2.0-79958148943OAI: oai:DiVA.org:kth-34657DiVA: diva2:426890
FunderSwedish Research Council
QC 201106272011-06-272011-06-132013-01-29Bibliographically approved