| 1. |
- de Maré, Sofia W., et al.
(författare)
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Structural Basis for Glycerol Efflux and Selectivity of Human Aquaporin 7
- 2020
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Ingår i: Structure. - : Elsevier BV. - 0969-2126. ; 28:2, s. 3-222
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Tidskriftsartikel (refereegranskat)abstract
- AQP7 is an important glycerol channel in human adipocytes, and its dysfunction is linked to metabolic disorders. The high-resolution X-ray structures of AQP7 unravels the molecular details of how glycerol travels through the channel and provide a structural basis for development of small-molecule drugs for targeting AQP7.
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| 2. |
- Huang, Peng, et al.
(författare)
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Cryo-EM structure supports a role of AQP7 as a junction protein
- 2023
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 14, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Aquaglyceroporin 7 (AQP7) facilitates glycerol flux across the plasma membrane with a critical physiological role linked to metabolism, obesity, and associated diseases. Here, we present the single-particle cryo-EM structure of AQP7 determined at 2.55 Å resolution adopting two adhering tetramers, stabilized by extracellularly exposed loops, in a configuration like that of the well-characterized interaction of AQP0 tetramers. The central pore, in-between the four monomers, displays well-defined densities restricted by two leucine filters. Gas chromatography mass spectrometry (GC/MS) results show that the AQP7 sample contains glycerol 3-phosphate (Gro3P), which is compatible with the identified features in the central pore. AQP7 is shown to be highly expressed in human pancreatic α- and β- cells suggesting that the identified AQP7 octamer assembly, in addition to its function as glycerol channel, may serve as junction proteins within the endocrine pancreas.
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| 3. |
- Huang, Peng, et al.
(författare)
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Molecular basis for human aquaporin inhibition
- 2024
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 1091-6490. ; 121:7
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Tidskriftsartikel (refereegranskat)abstract
- Cancer invasion and metastasis are known to be potentiated by the expression of aquaporins (AQPs). Likewise, the expression levels of AQPs have been shown to be prognostic for survival in patients and have a role in tumor growth, edema, angiogenesis, and tumor cell migration. Thus, AQPs are key players in cancer biology and potential targets for drug development. Here, we present the single-particle cryo-EM structure of human AQP7 at 3.2-Å resolution in complex with the specific inhibitor compound Z433927330. The structure in combination with MD simulations shows that the inhibitor binds to the endofacial side of AQP7. In addition, cancer cells treated with Z433927330 show reduced proliferation. The data presented here serve as a framework for the development of AQP inhibitors.
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| 4. |
- Huang, Peng, et al.
(författare)
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The intracellular helical bundle of human glucose transporter GLUT4 is important for complex formation with ASPL
- 2023
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Ingår i: FEBS Open Bio. - 2211-5463. ; 13:11, s. 2094-2107
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Tidskriftsartikel (refereegranskat)abstract
- Glucose transporters (GLUTs) are responsible for transporting hexose molecules across cellular membranes. In adipocytes, insulin stimulates glucose uptake by redistributing GLUT4 to the plasma membrane. In unstimulated adipose-like mouse cell lines, GLUT4 is known to be retained intracellularly by binding to TUG protein, while upon insulin stimulation, GLUT4 dissociates from TUG. Here, we report that the TUG homolog in human, ASPL, exerts similar properties, i.e., forms a complex with GLUT4. We describe the structural details of complex formation by combining biochemical assays with cross-linking mass spectrometry and computational modeling. Combined, the data suggest that the intracellular domain of GLUT4 binds to the helical lariat of ASPL and contributes to the regulation of GLUT4 trafficking by cooperative binding.
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| 5. |
- Kanje, Sara, 1986-, et al.
(författare)
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Protein engineering allows for mild affinity-based elution of therapeutic antibodies
- 2018
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Ingår i: Journal of Molecular Biology. - : Elsevier. - 0022-2836 .- 1089-8638. ; 430:18, s. 3427-3438
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Tidskriftsartikel (refereegranskat)abstract
- Presented here is an engineered protein domain, based on Protein A, that displays a calcium-dependent binding to antibodies. This protein, ZCa, is shown to efficiently function as an affinity ligand for mild purification of antibodies through elution with ethylenediaminetetraacetic acid. Antibodies are commonly used tools in the area of biological sciences and as therapeutics, and the most commonly used approach for antibody purification is based on Protein A using acidic elution. Although this affinity-based method is robust and efficient, the requirement for low pH elution can be detrimental to the protein being purified. By introducing a calcium-binding loop in the Protein A-derived Z domain, it has been re-engineered to provide efficient antibody purification under mild conditions. Through comprehensive analyses of the domain as well as the ZCa–Fc complex, the features of this domain are well understood. This novel protein domain provides a very valuable tool for effective and gentle antibody and Fc-fusion protein purification
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| 6. |
- Krintel, Christian, et al.
(författare)
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Binding of a negative allosteric modulator and competitive antagonist can occur simultaneously at the ionotropic glutamate receptor GluA2
- 2021
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Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 288:3, s. 995-1007
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Tidskriftsartikel (refereegranskat)abstract
- Ionotropic glutamate receptors are ligand-gated ion channels governing neurotransmission in the central nervous system. Three major types of antagonists are known for the AMPA-type receptor GluA2: competitive, non-competitive (i.e. negative allosteric modulators; NAMs) used for treatment of epilepsy, and uncompetitive antagonists. We here report a 4.65 Å resolution X-ray structure of GluA2, revealing that four molecules of the competitive antagonist ZK200775 and four molecules of the NAM GYKI53655 are capable of binding at the same time. Using negative stain electron microscopy, we show that GYKI53655 alone or ZK200775/GYKI53655 in combination predominantly result in compact receptor forms. The agonist AMPA provides a mixed population of compact and bulgy shapes of GluA2 not impacted by addition of GYKI53655. Taken together, this suggests that the two different mechanisms of antagonism that lead to channel closure are independent and that the distribution between bulgy and compact receptors primarily depends on the ligand bound in the glutamate binding site.
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| 7. |
- Venskutonytė, Raminta, et al.
(författare)
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Expression and purification of rat glucose transporter 1 in Pichia pastoris
- 2018
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Ingår i: Methods in Molecular Biology. - New York, NY : Springer New York. - 1064-3745. ; 1713
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Bokkapitel (refereegranskat)abstract
- Large amounts of pure and homogenous protein are a prerequisite for several biochemical and biophysical analyses, and in particular if aiming at resolving the three-dimensional protein structure. Here we describe the production of the rat glucose transporter 1 (GLUT1), a membrane protein facilitating the transport of glucose in cells. The protein is recombinantly expressed in the yeast Pichia pastoris. It is easily maintained and large-scale protein production in shaker flasks, as commonly performed in academic research laboratories, results in relatively high yields of membrane protein. The purification protocol describes all steps needed to obtain a pure and homogenous GLUT1 protein solution, including cell growth, membrane isolation, and chromatographic purification methods.
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| 8. |
- Venskutonytė, Raminta, et al.
(författare)
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Structural characterization of the microbial enzyme urocanate reductase mediating imidazole propionate production
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- The human microbiome can produce metabolites that modulate insulin signaling. Type 2 diabetes patients have increased circulating concentrations of the microbially produced histidine metabolite, imidazole propionate (ImP) and administration of ImP in mice resulted in impaired glucose tolerance. Interestingly, the fecal microbiota of the patients had increased capacity to produce ImP, which is mediated by the bacterial enzyme urocanate reductase (UrdA). Here, we describe the X-ray structures of the ligand-binding domains of UrdA in four different states, representing the structural transitions along the catalytic reaction pathway of this unexplored enzyme linked to disease in humans. The structures in combination with functional data provide key insights into the mechanism of action of UrdA that open new possibilities for drug development strategies targeting type 2 diabetes. Imidazole propionate (ImP) produced by gut microbiota has been associated with type 2 diabetes. Here, the authors present crystal structures of the ImP biosynthesis enzyme urocanate reductase in four different states, providing molecular insights into its catalytic mechanism.
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| 9. |
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