Surfactant protein B labelled with [99mTc(CO)3(H2O)3]+ retains biological activity in vitro

Amann, Anton; Decristoforo, Clemens; Ott, Ingo; Wenger, Martin; Bader, Dietmar; Alberto, Roger; Pütz, G.

doi:10.1016/s0969-8051(01)00192-5

Cited by 31 publications

(9 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Histidine has been demonstrated to be the favoured [ 99m Tc(CO) 3 ] + -binding ligand among amino acids and labelling efficiency and stability increase with increased number of engineered histidines [2]. Direct labelling of non-His-tag proteins with [ 99m Tc(CO) 3 ] + has previously resulted in poor stability and low labelling efficiency and specific activity, indicating that other potential amino acid side chains donor groups such as thiol, thioether, carboxylate and amine do not make a significant contribution in the absence of histidines [3-9]. Modification of the His-tag sequence from HHHHHH to HEHEHE in order to improve tracer biodistribution also resulted in reduced labelling efficiency [10,11].…”

Section: Introductionmentioning

confidence: 99%

Optimising the radiolabelling properties of technetium tricarbonyl and His-tagged proteins

et al. 2014

View full text Add to dashboard Cite

BackgroundTo date, the majority of protein-based radiopharmaceuticals have been radiolabelled using non-site-specific conjugation methods, with little or no control to ensure retained protein function post-labelling. The incorporation of a hexahistidine sequence (His-tag) in a recombinant protein can be used to site-specifically radiolabel with 99mTc-tricarbonyl ([99mTc(CO)3]+). This chemistry has been made accessible via a technetium tricarbonyl kit; however, reports of radiolabelling efficiencies and specific activities have varied greatly from one protein to another. Here, we aim to optimise the technetium tricarbonyl radiolabelling method to produce consistently >95% radiolabelling efficiencies with high specific activities suitable for in vivo imaging.MethodsFour different recombinant His-tagged proteins (recombinant complement receptor 2 (rCR2) and three single chain antibodies, α-CD33 scFv, α-VCAM-1 scFv and α-PSMA scFv), were used to study the effect of kit volume, ionic strength, pH and temperature on radiolabelling of four proteins.ResultsWe used 260 and 350 μL [99mTc(CO)3]+ kits enabling us to radiolabel at higher [99mTc(CO)3]+ and protein concentrations in a smaller volume and thus increase the rate at which maximum labelling efficiency and specific activity were reached. We also demonstrated that increasing the ionic strength of the reaction medium by increasing [Na+] from 0.25 to 0.63 M significantly increases the rate at which all four proteins reach a >95% labelling efficiency by at least fourfold, as compared to the conventional IsoLink® kit (Covidien, Petten, The Netherlands) and 0.25 M [Na+].ConclusionWe have found optimised kit and protein radiolabelling conditions suitable for the reproducible, fast, efficient radiolabelling of proteins without the need for post-labelling purification.

show abstract

Section: Introductionmentioning

confidence: 99%

Optimising the radiolabelling properties of technetium tricarbonyl and His-tagged proteins

et al. 2014

View full text Add to dashboard Cite

show abstract

“…5,6 Investigations by Egli et al 7 showing that histidine was the most potent ligand among other amino acids, have led to the direct radiolabelling of peptides or proteins. [7][8][9] Nevertheless, the yields are correlated to the number of histidine residues present on the primary structure, making the 99m Tc-tricarbonyl core not suitable for the radiolabelling of every protein. For example, annexin V, a 33 kDa protein with only three histidine residues 10,11 shows a disappointing yield of 40% when labelled with 99m Tc-tricarbonyl.…”

Section: Introductionmentioning

confidence: 99%

Improvement in radiolabelling proteins with the99mTc-tricarbonyl-core [99mTc(CO)3]+, by thiol-derivatization with iminothiolane: application to γ-globulins and annexin V

Biechlin

d′Hardemare

Fraysse

et al. 2005

J Label Compd Radiopharm

View full text Add to dashboard Cite

SummaryThe aim of this study was to improve the radiolabelling of proteins with the 99m Tctricarbonyl-[Tc(I)(CO) 3 ] + core by introducing thiol groups to their structure. To achieve this goal, g-globulins and annexin V were derivatized with mercaptobutyrimidyl groups (MBG) after reaction with 2-iminothiolane. The optimal conditions permitted attachment of an average of 3.3 thiol groups on g-globulins and 1.0 to annexin V. The radiolabelling assays were carried out by incubating 3.2 nmol of either g-globulin-SH or unmodified g-globulin with 60 MBq 99m Tc-tricarbonyl produced from an Isolink 1 kit (Mallinckrodt) under different reaction conditions. Results clearly showed that the introduction of three MBG could double the radiolabelling yields to more than 90% in a short time (30 mn, 378C). Such results would never have been reached with unmodified g-globulins alone. Under the same conditions when using 1-2 nmol derivatized annexin V, the average radiolabelling yield was 55% against 19% with the unmodified protein. The 99m Tc-tricarbonyl-conjugates were challenged with cysteine or histidine and showed good stability.

show abstract

“…While the higher oxidation states of technetium and rhenium continue to witness vigorous development as platforms for radiopharmaceuticals, it is noteworthy that the most successful technetium-based diagnostic is the low oxidation state Tc(I)-hexakis(isonitrile) complex [ 99m Tc(NCR) 6 ] + . 110 In recent years, there has been a renaissance of interest in the organometallic chemistry of technetium and rhenium for biological applications as a result of the work of Jaouen 111 and the seminal contributions of Alberto et al [112][113][114][115][116][117][118][119][120][121][122][123][124] to technetium-carbonyl chemistry. The key observation is that the permetallate salt MO Extensive studies of chemistry of the {Tc(CO) 3 } + core with a variety of chelating ligands demonstrate that tridentate ligands are most effective in substituting the aqua ligands to provide chemically robust materials.…”

Section: The Coordination Chemistry Of the Group 7 Transition Metalsmentioning

confidence: 99%

Single amino acid chelates (SAAC): a strategy for the design of technetium and rhenium radiopharmaceuticals

Bartholomä

Valliant

Maresca³

et al. 2009

Chem. Commun.

179

142

View full text Add to dashboard Cite

Radiolabeled biomolecules can be used to visualize a variety of diseases through interaction with specific cell receptors. A key step is the introduction of a molecular entity that allows facile labeling with the medically useful radionuclide (99m)Tc without significant alteration of the structure and function of the biomolecule. One strategy focuses on the design of single amino acid chelates (SAACs), novel bifunctional chelators constructed from derivatized amino acids or amino acid analogues. The chelating terminus of the SAAC has been designed for effective coordination to the {(99m)Tc(CO)(3)}(+) core, while the other terminus allows incorporation into any position along a peptide sequence or into a variety of biomolecules. In applications to peptidic materials, the approach affords significant flexibility in the choice of donors for (99m)Tc coordination combined with the considerable advantages of routine solid phase synthetic techniques. The methodology allows libraries of peptide-based (99m)Tc(i) and (186,188)Re(i) radiopharmaceuticals to prepared using conventional automated peptides synthesis. Other biomolecules, including nucleosides, carbohydrates, folic acid and vitamin B12 are also readily modified using analogous methods. The approach also allows the preparation of isostructural (99m)Tc and Re complexes for the correlation of in vivo and in vitro imaging studies.

show abstract

Surfactant protein B labelled with [99mTc(CO)3(H2O)3]+ retains biological activity in vitro

Cited by 31 publications

References 8 publications

Optimising the radiolabelling properties of technetium tricarbonyl and His-tagged proteins

Optimising the radiolabelling properties of technetium tricarbonyl and His-tagged proteins

Improvement in radiolabelling proteins with the99mTc-tricarbonyl-core [99mTc(CO)3]+, by thiol-derivatization with iminothiolane: application to γ-globulins and annexin V

Single amino acid chelates (SAAC): a strategy for the design of technetium and rhenium radiopharmaceuticals

Contact Info

Product

Resources

About