3CCK

Human CD69

Summary for 3CCK

• Entry DOI: 10.2210/pdb3cck/pdb
• Related: 1e87 1e8i 1fm5
• Descriptor: Early activation antigen CD69, CHLORIDE ION (3 entities in total)
• Functional Keywords: leukocyte activation, c-type lectin, refolding, stability, ligand binding, tumor therapies, glycoprotein, membrane, phosphoprotein, signal-anchor, transmembrane, immune system
• Biological source: Homo sapiens (Human)
• Cellular location: Membrane; Single-pass type II membrane protein: Q07108
• Total number of polymer chains: 2
• Total formula weight: 27719.47

Authors

Brynda, J.,Vanek, O.,Rezacova, P. (deposition date: 2008-02-26, release date: 2008-11-25, Last modification date: 2024-11-20)

Primary citation

Vanek, O.,Nalezkova, M.,Kavan, D.,Borovickova, I.,Pompach, P.,Novak, P.,Kumar, V.,Vannucci, L.,Hudecek, J.,Hofbauerova, K.,Kopecky, V.,Brynda, J.,Kolenko, P.,Dohnalek, J.,Kaderavek, P.,Chmelik, J.,Gorcik, L.,Zidek, L.,Sklenar, V.,Bezouska, K.
Soluble recombinant CD69 receptors optimized to have an exceptional physical and chemical stability display prolonged circulation and remain intact in the blood of mice
Febs J., 275:5589-5606, 2008

PubMed Abstract: We investigated the soluble forms of the earliest activation antigen of human leukocyte CD69. This receptor is expressed at the cell surface as a type II homodimeric membrane protein. However, the elements necessary to prepare the soluble recombinant CD69 suitable for structural studies are a matter of controversy. We describe the physical, biochemical and in vivo characteristics of a highly stable soluble form of CD69 obtained by bacterial expression of an appropriate extracellular segment of this protein. Our construct has been derived from one used for CD69 crystallization by further optimization with regard to protein stability, solubility and easy crystallization under conditions promoting ligand binding. The resulting protein is stable at acidic pH and at temperatures of up to 65 degrees C, as revealed by long-term stability tests and thermal denaturation experiments. Protein NMR and crystallography confirmed the expected protein fold, and revealed additional details of the protein characteristics in solution. The soluble CD69 refolded in a form of noncovalent dimers, as revealed by gel filtration, sedimentation velocity measurements, NMR and dynamic light scattering. The soluble CD69 proved to be remarkably stable in vivo when injected into the bloodstream of experimental mice. More than 70% of the most stable CD69 proteins is preserved intact in the blood 24 h after injection, whereas the less stable CD69 variants are rapidly taken up by the liver.

PubMed: 18959746
DOI: 10.1111/j.1742-4658.2008.06683.x

Experimental method

X-RAY DIFFRACTION (1.8 Å)