Zakład Fizyki Makromolekularnej
Strona główna


od 2020-09-20

Dr Witold Gospodarczyk  | 2011-10 <> 2018-03


Publikacje      Projekty                Licencjusze      Seminaria


Gospodarczyk W., Kozak M.

The severe impact of in vivo-like microfluidic flow and the influence of gemini surfactants on amyloid aggregation of hen egg white lysozyme The formation of amyloid plaques is being intensively studied, as this process underlies severe human diseases, including Alzheimer's disease, and the exact mechanism of this specific aggregation has not been resolved yet. The investigation of its formation is accompanied by the search for substances inhibiting this aggregation process. Here we studied the process of hen egg white lysozyme (HEWL) amyloid aggregation process in bulk solution within a time scale of about a week. We also examined the influence of four dicationic (gemini) surfactants, including 3,3′-[1,6-(2,5-dioxahexane)]bis-(1-dodecylimidazolium) dichloride (oxyC2), as well as selected reference sulfobetaines, on the aggregation process and found that at certain concentrations gemini surfactants remarkably inhibited amyloidogenesis. A microfluidic system was designed to mimic the in vivo-like conditions of flow in order to assess the influence of flow on the amyloid formation process. The flow was found to induce severe amyloid formation in just a few hours of exposition to the conditions which without flow would induce amyloidogenesis within a few days. The results shed light on the mechanisms responsible for the amyloid aggregation process and make an important contribution to understanding of the process.

RSC Advances, 7, 10973-10984 (2017)

DOI: 10.1039/c6ra26675d   (Pobrane:  2021-01-10)


Gospodarczyk W., Kozak M.

Interaction of two imidazolium gemini surfactants with two model proteins BSA and HEWL Gemini surfactants and their interactions with proteins have gained considerable scientific interest, especially when amyloidogenic proteins are taken into account. In this work, the influence of two selected dicationic (gemini) surfactants (3,3'-[1,8-(2,7-dioxaoctane)]bis(1-dodecylimidazolium) chloride and 3,3'-[1,12-(2,11-dioxadodecane)]bis(1-dodecylimidazolium) chloride) on two model proteins, bovine serum albumin (BSA) and hen egg white lysozyme (HEWL), have been investigated. A pronounced and sophisticated influence on BSA structure has been revealed, including a considerable change of protein radius of gyration as well as substantial alteration of its secondary structure. Radius of gyration has been found to rise significantly with addition of surfactants and to fall down for high surfactants concentration. Similarly, a remarkable fall of secondary structure (alpha-helix content) has been observed, followed by its partial retrieval for high surfactants concentration. A strong aggregation of BSA has been observed for a confined range of surfactants concentrations as well. In case of HEWL-gemini system, on the other hand, the protein-surfactant interaction was found to be weak. Molecular mechanisms explaining such behaviour of protein-surfactant systems have been proposed. The differences of properties of both studied surfactants have also been discussed.

Colloid and Polymer Science, 293(10), 2855-2866 (2015)

DOI: 10.1007/s00396-015-3671-z


Gospodarczyk W., Szutkowski K., Kozak M.

Interaction of Bovine Serum Albumin (BSA) with novel gemini surfactants studied by synchrotron radiation scattering (SR-SAXS), circular dichroism (CD) and nuclear magnetic resonance (NMR) The interaction of three dicationic (gemini) surfactants-3,3'-[1,6-(2,5-dioxahexane)]bis(1-dodecylimidazolium) chloride (oxyC2), 3,3'-[1,16-(2,15-dioxahexadecane)]bis(1-dodecylimidazolium) chloride (oxyC12), and 1,4-bis(butane)imidazole-1-yl-3-dodecylimidazolium chloride (C4)-with bovine serum albumin (BSA) has been studied by the use of small-angle X-ray scattering (SAXS), circular dichroism (CD), and H-1 nuclear magnetic resonance diffusometry. The results of CD studies show that the conformation of BSA was changed dramatically in the presence of all studied surfactants. The greater decrease (from 56 to 24%) in the alpha-helical structure of BSA was observed for oxyC2 surfactant. The radii of gyration estimated from SAXS data varied between 3 and 26 nm for the BSA/oxyC2 and BSA/oxyC12 systems. The hydrodynamic radius of the BSA/surfactant system estimated from NMR diffusometry varies between 5 and 11 nm for BSA/oxyC2 and 5 and 8 nm for BSA/oxyC12.

Journal of Physical Chemistry B, 118(29), 8652-8661 (2014)

DOI: 10.1021/jp5047485


Gospodarczyk W., Urbaniak M., Stobiecki F., Szymański B.

Giant magnetoresistance of [Ni80Fe20/Au/Co/Au](N) multilayers deposited on flexible substrates Magnetic hysteresis and magnetoresistance of[Ni80Fe20/Au/Co/Au](10) multilayers displaying giant magnetoresistance and sputtered on a flexible polypropylene substrates (an adhesive tape) is investigated. The magnetoresistive properties are very similar to those found in films prepared under the same conditions on Si(100) substrates. It is demonstrated, too, that a bendability of the substrates can be utilized to form cylindrically shaped magnetoresistive sensors with reduced anisotropy of the effect.

Acta Physica Polonica A, 121(5-6), 1234-1236 (2012)

DOI: 10.12693/APhysPolA.121.1234

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