Study on efficiency of oriented immobilization of antibodies on the SPR sensor surface using Staphylococcal protein A or its recombinant analogue

• Published in: Biopolimery i kletka Vol. 36; no. 4; pp. 271 - 278
• Main Authors: Bakhmachuk, A. O., Gorbatiuk, O. B., Rachkov, A. E., Soldatkin, A. P.
• Format: Journal Article
• Language: English
• Published: Kiev Natsional'na Akademiya Nauk Ukrainy - National Academy of Sciences of Ukraine 2020
• Subjects: Biosensors; Immobilization; Immunoglobulin G; Protein A; Proteins; Sensors; Surface plasmon resonance
• ISSN: 0233-7657; 1993-6842
• DOI: 10.7124/bc.000A32

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.