Determination of average number of chelators conjugated totrastuzumab using a MALDI-TOF MS

Sterjova Arev, Marija and Dzodic, Predrag and Dimovski, Aleksandar and Davalieva, Katarina and Kiprijanovska, Sanja and Drakalska, Elena and Janevik-Ivanovska, Emilija (2019) Determination of average number of chelators conjugated totrastuzumab using a MALDI-TOF MS. In: VII Congress of Pharmacy with International Participation, Borovec.

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Aims: The importance of trastuzumab (Tr) conjugation with bifunctional chelators (BFCs) in different molar ratio are presented with this study. A successful radiolabeling can be achieved after binding of optimal number of BFCs (4-5) per monoclonal antibody (mAb). The aim of our examination is to show that using a different BFCs in different molar ratio (p-SCN-Bn-DTPA – 1:10, 1:20, 1:50; p-SCN-Bn-DOTA – 1:20; p-SCN-Bn-1B4M-DTPA – 1:10, 1:20, 1:50) will achieve enough binding of the BFCs to Tr and formulation of immunoconjugates for further radiolabeling.
Material and methods: Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) was employed for determination of average number of BFCs. Resuspension solution (30% ACN/70% 0.1 TFA) was added to the samples and an aliquot of 1 μl of the final sample was applied to the well plate template and mixed with 1 μl of matrix (20 mg/ml Sinapinic acid in 50% ACN/50% 0.1 TFA). Acquisition mass range of the instrument is 100-300000 Da.
Results: An optimal number of BFCs were calculated in all samples. There was no significant difference in the number of the attached chelating groups by higher excess of the chelators: p-SCN-Bn-DTPA-Tr [1:10 (5 groups); 1:20 (4.8 groups); 1:50 (5.3 groups)]; p-SCN-Bn-DOTA-Tr 1:20 (4.9 groups); p-SCN-Bn-1B4M-DTPA [1:10 (4.9 groups); 1:20 (4.5 groups); 1:50 (4.3 groups)].
Conclusion: MALDI-TOF MS calculations have shown successful conjugations and formulated immunoconjugates are protentional compounds for further 90Y and 177Lu radiolabeling.

Item Type: Conference or Workshop Item (Poster)
Subjects: Medical and Health Sciences > Basic medicine
Divisions: Faculty of Medical Science
Depositing User: Marija Arev
Date Deposited: 26 Nov 2019 13:34
Last Modified: 26 Nov 2019 13:34

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