TY - JOUR
T1 - Influence of Histidine-Containing Tags on the Biodistribution of ADAPT Scaffold Proteins
AU - Lindbo, Sarah
AU - Garousi, Javad
AU - Åstrand, Mikael
AU - Honarvar, Hadis
AU - Orlova, Anna
AU - Hober, Sophia
AU - Tolmachev, Vladimir
N1 - Funding Information:
The authors would like to thank Dr. Nilvebrant for fruitful discussions. This research was financially supported by grants from the Swedish Cancer Society (grant CAN 2015/350) and the Swedish Research Council (grant 2015-02353, 621-2012- 5088).
Publisher Copyright:
© 2016 American Chemical Society.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/3/16
Y1 - 2016/3/16
N2 - 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 99mTc(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, 99mTc or 111In. The labeling with 99mTc(CO)3 utilized the histidine-containing tags, while 111In was attached through a maleimido derivative of DOTA conjugated to the N-terminus. For 111In-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 111In-(HE)3-ADAPT6 and H6-ADAPT6 at later time points. Interestingly, in the case of 99mTc, 99mTc(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.
AB - 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 99mTc(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, 99mTc or 111In. The labeling with 99mTc(CO)3 utilized the histidine-containing tags, while 111In was attached through a maleimido derivative of DOTA conjugated to the N-terminus. For 111In-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 111In-(HE)3-ADAPT6 and H6-ADAPT6 at later time points. Interestingly, in the case of 99mTc, 99mTc(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.
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U2 - 10.1021/acs.bioconjchem.5b00677
DO - 10.1021/acs.bioconjchem.5b00677
M3 - Article
C2 - 26781756
AN - SCOPUS:84962209236
VL - 27
SP - 716
EP - 726
JO - Bioconjugate Chemistry
JF - Bioconjugate Chemistry
SN - 1043-1802
IS - 3
ER -