Ana Tesouro Vallina

Publications (2)18.41 Total impact

• Article: Endogenous phosphatidylcholine and a long spacer ligand stabilize the lipid-binding groove of CD1b.

  Luis F Garcia-Alles, Kees Versluis, Laurent Maveyraud, Ana Tesouro Vallina, Sebastiano Sansano, Nana Fatimath Bello, Hans-Jürgen Gober, Valérie Guillet, Henri de la Salle, Germain Puzo, Lucia Mori, Albert J R Heck, Gennaro De Libero, Lionel Mourey
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  ABSTRACT: CD1 proteins present lipid antigens to T cells. The antigens are acquired in the endosomal compartments. This raises the question of how the large hydrophobic CD1 pockets are preserved between the moment of biosynthesis in the endoplasmic reticulum and arrival to the endosomes. To address this issue, the natural ligands associated with a soluble form of human CD1b have been investigated. Using isoelectric focusing, native mass spectrometry and resolving the crystal structure at 1.8 A resolution, we found that human CD1b is simultaneously associated with endogenous phosphatidylcholine (PC) and a 41-44 carbon atoms-long spacer molecule. The two lipids appear to work in concert to stabilize the CD1b groove, their combined size slightly exceeding the maximal groove capacity. We propose that the spacer serves to prevent binding of ligands with long lipid tails, whereas short-chain lipids might still displace the PC, which is exposed at the groove entrance. The data presented herein explain how the CD1b groove is preserved, and provide a rationale for the in vivo antigen-binding properties of CD1b.
  The EMBO Journal 09/2006; 25(15):3684-92. · 9.20 Impact Factor
• Article: Endogenous phosphatidylcholine and a long spacer ligand stabilize the lipid-binding groove of CD1b

  Luis F Garcia-Alles, Kees Versluis, Laurent Maveyraud, Ana Tesouro Vallina, Sebastiano Sansano, Nana Fatimath Bello, Hans-J|[uuml]|rgen Gober, Val|[eacute]|rie Guillet, Henri de la Salle, Germain Puzo, Lucia Mori, Albert JR Heck, Gennaro De Libero, Lionel Mourey
  [show abstract] [hide abstract]
  ABSTRACT: CD1 proteins present lipid antigens to T cells. The antigens are acquired in the endosomal compartments. This raises the question of how the large hydrophobic CD1 pockets are preserved between the moment of biosynthesis in the endoplasmic reticulum and arrival to the endosomes. To address this issue, the natural ligands associated with a soluble form of human CD1b have been investigated. Using isoelectric focusing, native mass spectrometry and resolving the crystal structure at 1.8 Å resolution, we found that human CD1b is simultaneously associated with endogenous phosphatidylcholine (PC) and a 41–44 carbon atoms-long spacer molecule. The two lipids appear to work in concert to stabilize the CD1b groove, their combined size slightly exceeding the maximal groove capacity. We propose that the spacer serves to prevent binding of ligands with long lipid tails, whereas short-chain lipids might still displace the PC, which is exposed at the groove entrance. The data presented herein explain how the CD1b groove is preserved, and provide a rationale for the in vivo antigen-binding properties of CD1b.
  The EMBO Journal 07/2006; 25(15):3684-3692. · 9.20 Impact Factor