Improvement in radiolabelling proteins with the 99mTc-tricarbonyl-core [99mTc(CO)3]+, by thiol-derivatization with iminothiolane: application to γ-globulins and annexin V
✍ Scribed by Marie-Laure Biechlin; Amaury du Moulinet d'Hardemare; Marc Fraysse; François-Noël Gilly; Alain Bonmartin
- Book ID
- 102376005
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- French
- Weight
- 143 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0022-2135
- DOI
- 10.1002/jlcr.999
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✦ Synopsis
The 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.