| 1. |
- Ahnström, Josefin, et al.
(author)
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HDL Stimulates apoM Secretion.
- 2010
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In: Protein & Peptide Letters. - 0929-8665. ; Jul 1, s. 1285-1289
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Journal article (peer-reviewed)abstract
- Apolipoprotein M (apoM) in human plasma is mainly associated with HDL. A retained signal peptide anchors apoM to the lipoproteins. To investigate the role of the signal peptide in the transfer of apoM from the synthesizing cell to the lipoproteins, wildtype apoM cDNA and the Q(22)A mutant, introducing a signal peptidase cleavage site, were used to stably transfect HEK293 cells, which intrinsically do not express apolipoproteins. When cultured under serum-free conditions, wildtype apoM was, in contrast to Q(22)A, poorly secreted. Addition of serum or purified HDL stimulated secretion of wildtype apoM, which was recovered in the medium incorporated in HDL. The liver cell line HepG2, which synthesizes HDL, was cultured under serum-free conditions and found to secrete apoM as part of an HDL-like particle. In conclusion, due to its retained signal peptide, apoM is poorly secreted unless HDL is either coexpressed or added to the culture medium.
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| 2. |
- Dobies, Maria, et al.
(author)
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The Dispersion of Water Proton Spin-Lattice Relaxation Rates in Aqueous Human Protein HC (alpha(1)-Microglobulin) Solutions
- 2009
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In: Protein & Peptide Letters. - 0929-8665. ; 16:12, s. 1496-1503
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Journal article (peer-reviewed)abstract
- The H-1 NMR Fast Field Cycling relaxometry was applied to study the molecular dynamics of the human protein HC (alpha(1)-microglobulin), its hydration and aggregation in solution state. The H-1 NMRD data have revealed the complex nature of the water/protein HC system resulting from the co-existence of monomer and dimer forms of the protein in solution as well as the presence of oligosaccharides linked to the polypeptide chain. A comparison of the average correlation time values obtained from the model-free fits with the values predicted on the basis of hydrodynamic tau(r) theory, suggests that the dynamics in solution state is governed mainly by the dimer form of the protein HC (the dominant contribution to the water proton-spin lattice relaxation comes from exchanging protons from the surface of the dimer). The existence of small number of oligomeric forms of the protein HC in solutions is postulated because of the two-step shape of water proton spin-lattice relaxation rate dispersion profiles.
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| 3. |
- Kahra, Dana, et al.
(author)
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Human Copper Chaperone Atox1 Translocates to the Nucleus but does not Bind DNA In Vitro.
- 2015
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In: Protein and peptide letters. - : Bentham Science. - 1875-5305 .- 0929-8665. ; 22:6, s. 532-8
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Journal article (peer-reviewed)abstract
- After Ctr1-mediated cell uptake, copper (Cu) is transported by the cytoplasmic Cu chaperone Atox1 to P1B type ATPases ATP7A and ATP7B in the Golgi network, for incorporation into Cudependent enzymes. Atox1 is a small 68-residue protein that binds Cu in a conserved CXXC motif; it delivers Cu to target domains in ATP7A/B via direct protein-protein interactions. Specific transcription factors regulating expression of the human Cu transport proteins have not been reported although Atox1 was recently suggested to have dual functionality such that it, in addition to its cytoplasmic chaperone function, acts as a transcription factor in the nucleus. To examine this hypothesis, here we investigated the localization of Atox1 in HeLa cells using fluorescence imaging in combination with in vitro binding experiments to fluorescently labeled DNA duplexes harboring the proposed promotor sequence. We found that whereas Atox1 is present in the nucleus in HeLa cells, it does not bind to DNA in vitro. It appears that Atox1 mediates transcriptional regulation via additional (unknown) proteins.
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| 4. |
- Kozak, M., et al.
(author)
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SAXS studies of human protein HC (alpha(1)-microglobulin)
- 2007
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In: Protein & Peptide Letters. - : Bentham Science Publishers Ltd.. - 0929-8665. ; 14:5, s. 425-429
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Journal article (peer-reviewed)abstract
- Protein HC is a low molecular weight heterogeneous glycoprotein widely distributed in human body fluids and belonging to the lipocalin superfamily. The monomer contains a single (183 amino acid residues long) peptide chain with 3 cysteine residues (2 of which form a disulfide bridge) and is glycosylated. The molecular mass of the glycosylated protein is about 27 kDa. Native gel electrophoresis results revealed partial oligomerisation of protein HC, which therefore was analysed by gel filtration. Two forms (monomer and dimer) of the protein HC were isolated. The SAXS data were recorded on an X33 camera using synchrotron radiation (lambda=0.15 nm) at X33 beamline at the DORIS storage ring of DESY (Hamburg, Germany). Solution scattering results permitted determination of the structural parameters of both forms of the protein studied. The monomer of protein HC is characterised by a radius of gyration R-G = 2.20 nm and D-max =63 nm and the dimer by R-G=2.99 nm and D-max = 9.5 nm.
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| 5. |
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| 6. |
- Linhult, M., et al.
(author)
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Affinity ligands for industrial protein purification
- 2005
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In: Protein peptide letters. - : Bentham Science Publishers Ltd.. - 0929-8665 .- 1875-5305. ; 12:4, s. 305-310
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Research review (peer-reviewed)abstract
- Significant efforts are put into the design of large-scale purification processes of proteins due to great demands regarding cost efficiency and safety. In order to design an effective purification scheme the unit operations need to be reduced to a minimum. In this review we are discussing proteinaceous ligands as well as small synthetic mimics for use in affinity chromatography for large-scale applications. Different advantages as well as drawbacks of the two approaches are outlined.
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| 7. |
- Palm-Espling, Maria, et al.
(author)
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Interaction between the anticancer drug cisplatin and the copper chaperone Atox1 in human melanoma cells
- 2014
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In: Protein Peptide Letters. - : Bentham Science Publishers Ltd.. - 0929-8665 .- 1875-5305. ; 21:1, s. 63-68
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Journal article (peer-reviewed)abstract
- Cisplatin (CisPt) is one of the most common anticancer drugs used against many severe forms of cancers. However, treatment with this drug causes many side effects and often, it results in the development of cell resistance. A majority of side effects as well as cell resistance are thought to develop due to CisPt interactions with proteins prior to reaching the nucleus and the DNA target. The copper (Cu) transport proteins Ctr1 and ATP7A/B have been implicated in cellular resistance of CisPt, possibly exporting the drug out of the cell. Recent in vitro work demonstrated that CisPt also interacts with the cytoplasmic Cu-chaperone Atox1, binding in or near the Cu-binding site, without expulsion of bound Cu. Whereas Ctr1 and ATP7B interactions with CisPt have been shown in vivo or ex vivo, there is no such information for Atox1-CisPt interactions. To address this, we developed a method to probe if CisPt interacts with Atox1 in human melanoma cells. Atox1-specific antibodies were linked to magnetic beads and used to immune-precipitate Atox1 from melanoma cells that had been pre-exposed to CisPt. Analysis of extracted Atox1 with inductively coupled plasma mass spectrometry demonstrated the presence of Pt in the protein fraction. Thus, CisPt-exposed human melanoma cells contain Atox1 molecules that bind some derivative of CisPt. This study gives the first indication for the intracellular presence of Atox1-CisPt complexes ex vivo. © 2014 Bentham Science Publishers.
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| 8. |
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| 9. |
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| 10. |
- Tanhaian, Abbas, et al.
(author)
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In Silico and In Vitro Investigation of a Likely Pathway for Anti-Cancerous Effect of Thrombocidin-1 as a Novel Anticancer Peptide
- 2020
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In: Protein peptide letters. - : Bentham Science Publishers Ltd. - 0929-8665 .- 1875-5305. ; 27:8, s. 751-762
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Journal article (peer-reviewed)abstract
- Background: Antimicrobial and antifungal activities of Thrombocidin-1 (TC-1) is shown previously, however, the anti-cancerous feature of this peptide is still uncovered. Objective: The objective is to evaluate anti-cancerous feature of recombinant TC-1. Methods: In this study, based on the significant similarity of rTC-1 and IL-8 in case of coding sequence, tertiary structure, and also docking and molecular dynamic simulation (MD) results with CXCR1, a receptor which has positive correlation with different cancers, a likely pathway for anti-cancerous effect of rTC-1 was proposed. In addition, the coding sequence of TC-1+6 x histidine (rTC-1) was inserted into the pET22b(+) vector and cloned and expressed by E. coli BL21 and finally purified through nickel affinity column. Afterward, the retrieved rTC-1 was used in MTT assay against mouse colon adenocarcinoma, hepatocellular carcinoma, chondrosarcoma, mouse melanoma, and breast adenocarcinoma cell lines to investigate its probable anticancer application. Results: Docking and MD simulation results showed that rTC-1 and IL-8 share almost the same residues in the interaction with CXCR1 receptor. Besides, the stability of the rTC-l_CXCR1(1-)(38) complex was shown during 100ns MD simulation. In addition, the successful expression and purification of rTC-1 depict an 8kD peptide. The IC50 results of MTT assay revealed that rTC-1 has cytotoxic effect on C26-A and SW1353 cancerous cell lines. Conclusion: Therefore, apart from probable anti-cancerous effect of rTC-1 on C26-A and SW1353 cell lines, this peptide may be able to mimic the anti-cancerous pathway of IL-8.
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