Influence of Histidine-Containing Tags on the Biodistribution of ADAPT Scaffold Proteins.
2016 (English)In: Bioconjugate chemistry, ISSN 1043-1802, E-ISSN 1520-4812, Vol. 27, no 3, 716-726 p.Article in journal (Refereed) Published
Engineered scaffold proteins (ESP) are high-affinity binders that can be used as probes for radionuclide imaging. Histidine-containing tags enable both efficient purification of ESP and radiolabeling with (99m)Tc(CO)3. Earlier studies demonstrated that the use of a histidine-glutamate-histidine-glutamate-histidine-glutamate (HE)3-tag instead of the commonly used hexahistidine (H6)-tag reduces hepatic uptake of radiolabeled ESP and short peptides. Here, we investigated the influence of histidine-containing tags on the biodistribution of a novel type of ESP, ADAPTs. A series of anti-HER2 ADAPT probes having H6- or (HE)3-tags in the N-termini were prepared. The constructs, (HE)3-ADAPT6 and H6-ADAPT6, were labeled with two different nuclides, (99m)Tc or (111)In. The labeling with (99m)Tc(CO)3 utilized the histidine-containing tags, while (111)In was attached through a maleimido derivative of DOTA conjugated to the N-terminus. For (111)In-labeled ADAPTs, the use of (HE)3 provided a significantly (p < 0.05) lower hepatic uptake at 1 h after injection, but there was no significant difference in hepatic uptake of (111)In-(HE)3-ADAPT6 and H6-ADAPT6 at later time points. Interestingly, in the case of (99m)Tc, (99m)Tc(CO)3-H6-ADAPT6 provided significantly (p < 0.05) lower uptake in a number of normal tissues and was more suitable as an imaging probe. Thus, the influence of histidine-containing tags on the biodistribution of the novel ADAPT scaffold proteins was different compared to its influence on other ESPs studied so far. Apparently, the effect of a histidine-containing tag on the biodistribution is highly dependent on the scaffold composition of the ESP.
Place, publisher, year, edition, pages
2016. Vol. 27, no 3, 716-726 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-286833DOI: 10.1021/acs.bioconjchem.5b00677ISI: 000372478600026PubMedID: 26781756OAI: oai:DiVA.org:uu-286833DiVA: diva2:922065
FunderSwedish Cancer Society, CAN 2015/350Swedish Research Council, 2015-02353, 621-2012-5088
First two authors (Lindbo and Garousi) contributed equally2016-04-212016-04-212016-05-04Bibliographically approved