6ZPD

gamma-tocopherol transfer protein

6ZPD の概要

• エントリーDOI: 10.2210/pdb6zpd/pdb
• 関連するPDBエントリー: 5MUE 5MUG
• 分子名称: 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)
• 機能のキーワード: sec-14 like, vitamin e, nanoparticle, transcytosis, lipid transport
• 由来する生物種: Homo sapiens (Human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 27659.88

構造登録者

Aeschimann, W.,Kammer, S.,Staats, S.,Stocker, A. (登録日: 2020-07-08, 公開日: 2020-12-02, 最終更新日: 2024-10-16)

主引用文献

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

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: 33197771
DOI: 10.1016/j.redox.2020.101773

実験手法

X-RAY DIFFRACTION (2.24 Å)