Biopolym. Cell. 2020; 36(4):271-278.
Molecular and Cell Biotechnologies
Study on efficiency of oriented immobilization of antibodies on the SPR sensor surface using Staphylococcal protein A or its recombinant analogue
1, 2Bakhmachuk A. O., 1, 3Gorbatiuk O. B., 1Rachkov A. E., 1, 2Soldatkin A. P.
  1. Institute of Molecular Biology and Genetics, NAS of Ukraine
    150, Akademika Zabolotnoho Str., Kyiv, Ukraine, 03143
  2. Institute of High Technologies,
    Taras Shevchenko National University of Kyiv
    2, korp.5, Pr. Akademika Hlushkova, Kyiv, Ukraine, 03022
  3. State Institute of Genetic and Regenerative Medicine, NAMS of Ukraine
    67, Vyshhorodska Str., Kyiv, Ukraine, 04114


Aim. Comparison of IgG-binding activity of Staphylococcal protein A (SPA) and recombinant SPA with specially introduced C-terminal cysteine residue (SPA-Cys) after their immobilization on a gold sensor surface of the surface plasmon resonance (SPR) spectrometer. Methods. SPA or SPA-Cys was immobilized on a gold sensor surface to form two variants of bioselective elements of biosensor. SPR spectrometry was used for detection of IgG-binding activity of the immobilized proteins. Results. The SPR sensor response to the immobilization of SPA was more than three times less than that to immobilization of SPA-Cys. SPA-Cys demonstrates also almost 4-fold advantage in the number of immobilized molecules. Moreover, the bioselective element based on SPA-Cys showed a much better capability of binding IgG than the bioselective element based on SPA. Conclusions. The study of the processes of immobilization of SPA or SPA-Cys on the sensor surface of SPR spectrometer, and the interactions of immobilized proteins with human IgG demonstrated obvious advantages of recombinant protein A.
Keywords: antibodies, recombinant Staphylococcal protein A, protein immobilization, surface plasmon resonance