ATR-IR and Raman spectoscropic characterization of p-SCN-Bn-DTPA and p-SCN-Bn-1B4M-DTPA trastuzumab conjugates

Sterjova, Marija and Dzodic, Predrag and Makreski, Petre and Janevik-Ivanovska, Emilija (2018) ATR-IR and Raman spectoscropic characterization of p-SCN-Bn-DTPA and p-SCN-Bn-1B4M-DTPA trastuzumab conjugates. In: 7th Balkan Congress of Nuclear Medicine, 9-12 May 2018, Sarajevo, BiH.

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Introduction: As powerful and non-destructive techniques, Attenuated total reflectance-infrared (ATR-IR) and Raman spectroscopy provide valuable molecular structure information and are convenient for verification of any changes in the native state of proteins. The purpose of this experimental work is to determine the secondary structure of trastuzumab after conjugation with (p-SCN-Bn-1B4M-DTPA (2-(4-isothiocyanatobenzyl)-6-methyl-diethylene-triaminepentaacetic acid) and p-SCN-Bn-DTPA (2-(4-izothiocyanatobenzyl)-diethylenetriaminepentaacetic acid)) by applying of these two techniques.
Material and methods: The 10- and 50-fold molar excess of chelators were conjugated with pure trastuzumab and freeze dried to solid state. Vibrational spectroscopy (Raman and ATR-IR) was applied for further physico-chemical examinations of lyophilized non-labeled samples by directly applying under the laser beam of the instrument. The spectra of conjugated samples were compared with naked trastuzumab purified from commercial product Herceptin®.
Results: The presence of characteristic amide bands (amide I, II and III bands) in ATR-IR and Raman spectra have indicated of retained native IgG1 structure of the antibody principally composed of β-sheets. The same as pure antibody, Raman spectra of conjugates contain the characteristic amide I band at ~1670 cm-1 and amide III band (1230-1300 cm-1). IR spectra of the samples also correspond with naked antibody and contain the amide I (1700-1600 cm-1), amide II (1480-1575 cm-1) and amide III bands (1255-1244 cm-1) specific for secondary structure of the proteins.
Conclusion: No integrity changes, physicochemical and structural modifications of trastuzumab after conjugation approve retained β-sheet structure of the antibody and support the opportunity for further development of radioimmunotherapeutics and diagnostic products active against HER2 positive breast tumors.

Item Type: Conference or Workshop Item (Poster)
Subjects: Medical and Health Sciences > Health sciences
Divisions: Faculty of Medical Science
Depositing User: Marija Arev
Date Deposited: 03 Dec 2018 08:57
Last Modified: 03 Dec 2018 08:57

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