[1] Univ Paris Sud, CNRS, UMR 8076, IFR 141, F-92296 Chatenay Malabry, France
[2] Univ Paris Sud, UMR 8612, CNRS, IFR 141, F-92296 Chatenay Malabry, France
[3] Univ Paris Sud, UPRES, EA 3535, IGR, F-94805 Villejuif, France
[4] CEA, SPI, BIO, Lab Neurovirol,DSV,DRM, F-92265 Fontenay Aux Roses, France
[5] IGR, IFR54, Serv Commun Spectrometrie Masse, F-94805 Villejuif, France