Molecule of the Month
October 2017
Crossing the Endothelial Barrier

α-Tocopherol Transfer Protein (α-TTP) is a liver protein responsible for Vitamin E (α-tocopherol) homeostasis in man [1]. The mechanisms by which vitamin E crosses endothelial barriers to enter the brain or the embryo is currently unknown.
We have demonstrated that in specific conditions that also require the presence of α-tocopherol, α-TTP can form nano-spherical particles. We have solved the X-ray structure of such nano-particles and demonstrated their capability of crossing a layer of primary human umbilical vein cells (HUVEC) a common cell culture model for endothelial tissues [2].

This work was carried out in the group of Prof. Achim Stocker.


  1. K. Ouahchi, M. Arita, H. Kayden, F. Hentati, M. B. Hamida, R. Sokol, H. Arai, K. Inoue, J.-L. Mandel, M. Koenig;
    "Ataxia with isolated vitamin E deficiency is caused by mutations in the α-tocopherol transfer protein"
    Nature Genetics, 1995, 9(2), 141-145; doi:10.1038/ng0295-141.
  2. W. Aeschimann, S. Staats, S. Kammer, N. Olieric, J.-M. Jeckelmann, D. Fotiadis, T. Netscher, G. Rimbach, M. Cascella, A. Stocker;
    "Self-assembled α-Tocopherol Transfer Protein Nanoparticles Promote Vitamin E Delivery Across an Endothelial Barrier"
    Scientific Reports, 2017, 7, 4970/1-13; doi:10.1038/s41598-017-05148-9.