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Environ 25 % des bronchites chroniques obstructives (BPCO) sont liées à des expositions professionnelles, notamment aux particules fines ou ultrafines (PF/PUF) qui peuvent induire un stress oxydant. Le diagnostic et l’évaluation de la sévérité de la BPCO reposent actuellement sur un test d’exploration fonctionnelle respiratoire (spirométrie) ne permettant ni le diagnostic précoce ni une détection des épisodes d’exacerbation. Des méthodes de mesure de biomarqueurs, notamment le 8-hydroxy-2′-deoxyguanosine (OHdG), le 8-isoprostane (isoP) et le malondialdehyde (MDA) dans des matrices non-invasives telles que le condensat d’air exhalé (EBC) et l’urine sont en cours de développement pour accéder aux informations biochimiques relatives au stress oxydant pulmonaire et systémique et faciliter le diagnostic. Néanmoins, leur validation en tant que biomarqueurs diagnostiques, nécessite d’établir les valeurs de référence dans une population saine non exposée et d’évaluer leur variabilité inter- et intra-individuelle.

Protein L is a multidomain cell-wall protein isolated from Peptostreptococcus magnus. It belongs to a group of proteins that contain repeated domains that are able to bind to Igs without stimulating an immune response, the most characterized of this group being Protein A (Staphylococcus aureus) and Protein G (Streptococcus). Both of these proteins bind predominantly to the interface of CH2-CH3 heavy chains, while Protein L binds exclusively to the VL domain of the κ-chain. The function of these proteins in vivo is not clear but it is thought that they enable the bacteria to evade the host's immune system. Two binding sites for κ-chain on a single Ig-binding domain from Protein L have recently been reported and we give evidence that one site has a 25–55-fold higher affinity for κ-chain than the second site.

Pyrococcus abyssi virus 1 (PAV1) was the first virus particle infecting a hyperthermophilic Euryarchaeota (Pyrococcus abyssi strain GE23) that has been isolated and characterized. It is lemon shaped and is decorated with a short fibered tail. PAV1 morphologically resembles the fusiform members of the family Fuselloviridae or the genus Salterprovirus. The 18?kb dsDNA genome of PAV1 contains 25 predicted genes, most of them of unknown function. To help assigning functions to these proteins, we have initiated structural studies of the PAV1 proteome. We determined the crystal structure of a putative protein of 137 residues (PAV1-137) at a resolution of 2.2?Å. The protein forms dimers both in solution and in the crystal. The fold of PAV1-137 is a four-a-helical bundle analogous to those found in some eukaryotic adhesion proteins such as focal adhesion kinase, suggesting that PAV1-137 is involved in protein-protein interactions.