| 1. |
- Chrabaszczewska, Magdalena, et al.
(författare)
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Structural characterization of covalently stabilized human cystatin c oligomers
- 2020
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 21:16
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Tidskriftsartikel (refereegranskat)abstract
- Human cystatin C (HCC), a cysteine-protease inhibitor, exists as a folded monomer under physiological conditions but has the ability to self-assemble via domain swapping into multimeric states, including oligomers with a doughnut-like structure. The structure of the monomeric HCC has been solved by X-ray crystallography, and a covalently linked version of HCC (stab-1 HCC) is able to form stable oligomeric species containing 10–12 monomeric subunits. We have performed molecular modeling, and in conjunction with experimental parameters obtained from atomic force microscopy (AFM), transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) measurements, we observe that the structures are essentially flat, with a height of about 2 nm, and the distance between the outer edge of the ring and the edge of the central cavity is ~5.1 nm. These dimensions correspond to the height and diameter of one stab-1 HCC subunit and we present a dodecamer model for stabilized cystatin C oligomers using molecular dynamics simulations and experimentally measured parameters. Given that oligomeric species in protein aggregation reactions are often transient and very highly heterogeneous, the structural information presented here on these isolated stab-1 HCC oligomers may be useful to further explore the physiological relevance of different structural species of cystatin C in relation to protein misfolding disease.
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| 2. |
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| 3. |
- Pikuła, Michał, et al.
(författare)
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Cystatin C peptidomimetic derivative with antimicrobial properties as a potential compound against wound infections
- 2017
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Ingår i: Bioorganic and Medicinal Chemistry. - : Elsevier BV. - 0968-0896. ; 25:4, s. 1431-1439
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Tidskriftsartikel (refereegranskat)abstract
- A peptidomimetic called A20 (Cystapep 1) structurally based upon the N-terminal fragment of human cystatin C is known to have strong antibacterial properties. A20 is characterized by high activity against several bacterial strains often isolated from infected wounds, including methicillin-resistant S. aureus (MRSA). In this work we wanted to explore the therapeutic potential of A20 in the treatment of wound infections. We examined, cytotoxicity, allergenicity and impact of A20 on the proliferation and viability of human keratinocytes. Furthermore, the previously described antimicrobial action of A20. has been confirmed here with reference strains of bacteria and extended by several other species. The A20 was highly active against Gram-positive bacteria with minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC) between 8 and 128. μg/mL. A20 did not affect proliferation of primary human keratinocytes in concentrations up to 50. μg/mL. At the same time, it did not activate Peripheral Blood Mononuclear Cells (PBMCs), including basophils or neutrophils in vitro. Interestingly A20 was found to display immunomodulatory functions as it influences the production of Th2 cytokines (IL-4 and IL-13) by activated PBMCs. It was also resistant to degradation for at least 48. h in human plasma. The results indicate that A20 is effective against the multiantibiotic-resistant bacteria and has a high safety profile, which makes it a promising antimicrobial drug candidate.
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| 4. |
- Szymańska, Aneta, et al.
(författare)
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Governing the monomer-dimer ratio of human cystatin C by single amino acid substitution in the hinge region
- 2009
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Ingår i: Acta Biochimica Polonica. - 0001-527X. ; 56:3, s. 455-463
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Tidskriftsartikel (refereegranskat)abstract
- Three dimensional domain swapping is one of the mechanisms involved in formation of insoluble aggregates of some amyloidogenic proteins. It has been proposed that proteins able to swap domains may share some common structural elements like conformationally constrained flexible turns/loops. We studied the role of loop L1 in the dimerization of human cystatin C using mutational analysis. Introduction of turn-favoring residues such as Asp or Asn into the loop sequence (in position 57) leads to a significant reduction of the dimer fraction in comparison with the wild type protein. On the other hand, introduction of a proline residue in position 57 leads to efficient dimer formation. Our results confirm the important role of the loop L1 in the dimerization process of human cystatin C and show that this process can be to some extent governed by single amino acid substitution.
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