KfrA plasmid protein monolayers on latex particles-electrokinetic measurements

Kujda, Marta; Adamczyk, Zbǐgniew; Jagura-Burdzy, Grażyna; Adamczyk, M.

doi:10.1016/j.colsurfb.2013.07.026

Cited by 8 publications

(6 citation statements)

References 25 publications

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“…The in vivo dimerization of KfrA R751 has been demonstrated experimentally earlier in the yeast two-hybrid system [10]. AFM measurements at low pH 3.5 showed that, in solution, the major form of KfrA R751 protein was tetrameric [27,30]. We performed additional analysis with purified KfrA R751 and KfrA RA3 treated with the cross-linking agent (glutaraldehyde) to verify whether the proteins are able to form other multimeric structures and whether experimental conditions affect the oligomeric state of the proteins.…”

Section: Kfra Proteins Can Self-assemble and Exist In Multiple Oligomeric States In Vitromentioning

confidence: 67%

Revealing biophysical properties of KfrA-type proteins as a novel class of cytoskeletal, coiled-coil plasmid-encoded proteins

et al. 2021

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Background DNA binding KfrA-type proteins of broad-host-range bacterial plasmids belonging to IncP-1 and IncU incompatibility groups are characterized by globular N-terminal head domains and long alpha-helical coiled-coil tails. They have been shown to act as transcriptional auto-regulators. Results This study was focused on two members of the growing family of KfrA-type proteins encoded by the broad-host-range plasmids, R751 of IncP-1β and RA3 of IncU groups. Comparative in vitro and in silico studies on KfrAR751 and KfrARA3 confirmed their similar biophysical properties despite low conservation of the amino acid sequences. They form a wide range of oligomeric forms in vitro and, in the presence of their cognate DNA binding sites, they polymerize into the higher order filaments visualized as “threads” by negative staining electron microscopy. The studies revealed also temperature-dependent changes in the coiled-coil segment of KfrA proteins that is involved in the stabilization of dimers required for DNA interactions. Conclusion KfrAR751 and KfrARA3 are structural homologues. We postulate that KfrA type proteins have moonlighting activity. They not only act as transcriptional auto-regulators but form cytoskeletal structures, which might facilitate plasmid DNA delivery and positioning in the cells before cell division, involving thermal energy.

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Section: Kfra Proteins Can Self-assemble and Exist In Multiple Oligomeric States In Vitromentioning

confidence: 67%

Revealing biophysical properties of KfrA-type proteins as a novel class of cytoskeletal, coiled-coil plasmid-encoded proteins

et al. 2021

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“…It should also be mentioned that the estimated relaxation time of KfrA R751 monolayer formation on latex particles, was ca. one second for the final latex concentration of 120 mg L −1 [11]. Therefore, the adsorption time of 900 s ensured that all protein molecules could adsorb on the latex particles.…”

Section: Kfra R751 Adsorption On Latex Particlesmentioning

confidence: 99%

“…KfrA from the broad-host range IncP-1b plasmid R751, the alphahelical protein studied in this work, is engaged in the plasmid inheritance process during cell division, but the molecular mechanism of KfrA action remains unclear [7][8][9]. Despite the major significance of this protein, few quantitative data concerning its physicochemical properties and its interactions with surfaces are available in the literature [10,11]. The main obstacle in performing thorough experiments is a limited stability of the protein under in vitro conditions because of its aggregation tendency and minor available quantities, usually 100-500 µg.…”

Section: Introductionmentioning

confidence: 99%

“…This prohibits the use of ordinary bulk methods, for example dynamic light scattering (DLS) or micro-electrophoretic measurements. In order to overcome these limitations, in previous works [10,11] an indirect method was developed where KfrA monolayers were formed on colloid carrier particles (polystyrene latex microspheres). Afterwards, electrokinetic properties of such stable monolayers were studied by using the micro-electrophoretic method.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, the main goal of this work is to develop a robust bead model of the KfrA molecule aggregates that facilitates the precise determination of the maximum coverage for various ionic strengths and molecule orientation in the monolayers formed on latex particles. The efficient random sequential adsorption (RSA) modeling is applied in these calculations where, in contrast to previous studies [10,11], protein interactions are considered via the screened Yukawa-type potential. The modeling is used for the interpretation of experimental data derived by the depletion method previously used for determining the adsorption isotherms of bovine serum albumin [12,13], human serum albumin [14][15][16][17] and immunoglobulins [18] on latex particles.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

High density monolayers of plasmid protein on latex particles: experiments and theoretical modeling

Kujda¹,

Adamczyk²,

Cieśla³

et al. 2015

J. Stat. Mech.

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Monolayers obtained by adsorption of the plasmid protein KfrA on negatively charged polystyrene latex particles under diffusion-controlled conditions at pH 3.5 were interpreted in terms of the random sequential adsorption (RSA) model. A quantitative agreement of the theoretical results derived from these calculations with experimental data was attained for the ionic strength from 0.15 up to 10−2 M. This confirmed the adsorption mechanism of KfrA molecules on latex in the form of tetramers up to 10−2 M. On the other hand, for the ionic strength of 10−3 M the experimental coverage agreed with theoretical predictions under the assumption that screening of electrostatic interaction is enhanced by the presence of counterions and negatively charged polymer chains stemming from latex particles.

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