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Kovács Boglárka

az alábbi absztraktok szerzői között szerepel:

Kovács Boglárka
Flagellin: a convenient protein in biosensorics

Aug 30 - szerda

11:15 – 11:30

Bioszenzorika és bio-nanotechnológia

E27

Flagellin: a convenient protein in biosensorics

Boglárka Kovács¹, András Saftics¹, Inna Székács¹, Hajnalka Jankovics², Sandor Kurunczi¹, Ferenc Vonderviszt², Robert Horvath¹

¹Nanobiosensorics Laboratory, Centre for Energy Research, Institute of Technical Physics and Materials Science, Budapest, Hungary

²Bio-nanosystem Laboratory, Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém, Hungary

Flagellin is the main building block of bacterial flagellar filaments. Since the filaments are located outside of the cells, cell lysis is not required to purify flagellin. Flagellin consists of 4 domains: D0, D1, D2, and D3. The D0 domain contains amphipathic helical regions with hydrophobic amino acids on one side of the helix. This part of flagellin is disordered in solution, but can be used to anchor the protein on hydrophobic surfaces with the D3 domain pointing towards the solution [1]. The hypervariable D3 domain situated on the filament surface is a largely independent part of the flagellin that can be removed or replaced without disturbing filament formation.

During our work we in-depth characterized the coatings created from flagellin, and influenced the adsorption of the protein with Hofmeister salts [1]. We applied genetically modified high affinity Ni-binding variant as receptor, and demonstrated the unique sensitivity of grating-coupled interferometry [2].

The monolayer of wild-type flagellin mimics the surface of the bacterial flagellar filament, and we hypothesized that oriented flagellin layers have bacteria-repellent properties. To prove this, we studied the adhesion of bacterial E. coli and human cancer cells on oriented wild-type flagellin layers [3,4].

Through genetic modification, specific oligopeptide segments can be also inserted into the D3 domain of flagellin, which can induce cell adhesion through integrin receptors. We studied cancer cell adhesion on the genetically engineered protein layers with label-free optical biosensors [4]. Mammalian cells can recognize flagellin in solution through Toll-like receptors, and the protein can cause innate immune system response. We are studying the above biological mechanisms and its consequences in the adhesion of the flagelljn exposed cells. Our results prove, that flagellin can be used in many ways in creating capture layers in biosensors.

References

[1] Kovacs, B.; Saftics, A.; Biro, A.; Kurunczi, S.; Szalontai, B.; Kakasi, B.; Vonderviszt, F.; Der, A.; Horvath, R. J. Phys. Chem. C 2018, 122 (37), 21375–21386.

[2] Jankovics, H.; Kovacs, B.; Saftics, A.; Gerecsei, T.; Tóth, É.; Szekacs, I.; Vonderviszt, F.; Horvath, R. Sci. Rep. 2020, 1–11.

[3] Kovacs, B.; Patko, D.; Klein, A.; Kakasi, B.; Saftics, A.; Kurunczi, S.; Vonderviszt, F.; Horvath, R. Sensors Actuators B Chem. 2018, 257, 839–845.

[4] Kovacs, B.; Patko, D.; Szekacs, I.; Orgovan, N.; Kurunczi, S.; Sulyok, A.; Khanh, N. Q.; Toth, B.; Vonderviszt, F.; Horvath, R. Acta Biomater. 2016, No. 42, 66–76.

Magyaródi Beatrix
Role of glycocalyx in cancer cell adhesion: kinetics of interactions from label-free optical biosensor measurements

Aug 30 - szerda

15:30 – 17:00

II. Poszterszekció

P46

Role of glycocalyx in cancer cell adhesion: kinetics of interactions from label-free optical biosensor measurements

Beatrix Magyaródi¹, Boglárka Kovács¹, Inna Székács¹, Robert Horvath¹

¹ Nanobiosensorics Laboratory, Research Centre for Energy Research, Institute for Technical Physics and Materials Science, Konkoly-Thege u 29-33, 1120 Budapest, Hungary

The glycocalyx is a sugar rich layer covering the surface of the cells.[1] It is composed of glycoproteins and proteoglycans. The cellular glycocalyx plays an important, but not yet understood, role in cellular signaling and metabolism, its disorders generate pathological process.[2] Interestingly, the thickness of the glycocalyx layer of cancer cells is significantly larger compared to that of healthy cells. This fact further highlights the importance of glycocalyx in tumor progression and treatment. In an earlier work, a regulatory mechanism of cellular glycocalyx in cancer adhesion was revealed using label-free optical biosensor, fluorescent microscopy, and cell surface charge measurements. [3]

The primary goal of our work is to study the role of glycocalyx components in cellular adhesion by employing various types of digesting methods. In these initial measurements we use a label-free, high-throughput, resonant waveguide grating-based optical biosensor. The instrument is well suited for monitoring of cellular adhesion kinetics in real-time, even at the single-cell level.[4]

Acknowledgment

This work was supported by the National Research, Development, and Innovation Office (Grant Numbers: PD 134195 for Z.Sz, PD 131543 for B.P., ELKH topic-fund, "Élvonal" KKP_19 TKP2022-EGA-04 grants)

References

[1] M. J. Paszek et al., “The cancer glycocalyx mechanically primes integrin-mediated growth and survival,” Nature, vol. 511, no. 7509, pp. 319–325, 2014, doi: 10.1038/nature13535.

[2] E. R. Cruz-Chu, A. Malafeev, T. Pajarskas, I. V. Pivkin, and P. Koumoutsakos, “Structure and response to flow of the glycocalyx layer,” Biophys. J., 2014, doi: 10.1016/j.bpj.2013.09.060.

[3] N. Kanyo et al., “Glycocalyx regulates the strength and kinetics of cancer cell adhesion revealed by biophysical models based on high resolution label-free optical data,” Sci. Rep., 2020, doi: 10.1038/s41598-020-80033-6.

[4] M. Sztilkovics et al., “Single-cell adhesion force kinetics of cell populations from combined label-free optical biosensor and robotic fluidic force microscopy,” Sci. Rep., 2020, doi: 10.1038/s41598-019-56898-7.