6ZPD
gamma-tocopherol transfer protein
Summary for 6ZPD
| Entry DOI | 10.2210/pdb6zpd/pdb |
| Related | 5MUE 5MUG |
| Descriptor | Alpha-tocopherol transfer protein, (2R)-2,5,7,8-TETRAMETHYL-2-[(4R,8R)-4,8,12-TRIMETHYLTRIDECYL]CHROMAN-6-OL, SULFATE ION, ... (6 entities in total) |
| Functional Keywords | sec-14 like, vitamin e, nanoparticle, transcytosis, lipid transport |
| Biological source | Homo sapiens (Human) |
| Total number of polymer chains | 1 |
| Total formula weight | 27659.88 |
| Authors | Aeschimann, W.,Kammer, S.,Staats, S.,Stocker, A. (deposition date: 2020-07-08, release date: 2020-12-02, Last modification date: 2024-10-16) |
| Primary citation | Aeschimann, W.,Kammer, S.,Staats, S.,Schneider, P.,Schneider, G.,Rimbach, G.,Cascella, M.,Stocker, A. Engineering of a functional gamma-tocopherol transfer protein. Redox Biol, 38:101773-101773, 2020 Cited by PubMed Abstract: α-tocopherol transfer protein (TTP) was previously reported to self-aggregate into 24-meric spheres (α-TTP) and to possess transcytotic potency across mono-layers of human umbilical vein endothelial cells (HUVECs). In this work, we describe the characterisation of a functional TTP variant with its vitamer selectivity shifted towards γ-tocopherol. The shift was obtained by introducing an alanine to leucine substitution into the substrate-binding pocket at position 156 through site directed mutagenesis. We report here the X-ray crystal structure of the γ-tocopherol specific particle (γ-TTP) at 2.24 Å resolution. γ-TTP features full functionality compared to its α-tocopherol specific parent including self-aggregation potency and transcytotic activity in trans-well experiments using primary HUVEC cells. The impact of the A156L mutation on TTP function is quantified in vitro by measuring the affinity towards γ-tocopherol through micro-differential scanning calorimetry and by determining its ligand-transfer activity. Finally, cell culture experiments using adherently grown HUVEC cells indicate that the protomers of γ-TTP, in contrast to α-TTP, do not counteract cytokine-mediated inflammation at a transcriptional level. Our results suggest that the A156L substitution in TTP is fully functional and has the potential to pave the way for further experiments towards the understanding of α-tocopherol homeostasis in humans. PubMed: 33197771DOI: 10.1016/j.redox.2020.101773 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.24 Å) |
Structure validation
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