[1] MAX PLANCK INST BIOPHYS CHEM, DEPT MOL GENET, D-37018 GOTTINGEN, GERMANY
[2] UNIV ROMA LA SAPIENZA, DIPARTIMENTO SCI BIOCHIM A ROSSI FANELLI, I-00185 ROME, ITALY
[3] UNIV ROMA LA SAPIENZA, CNR, CTR BIOL MOL, I-00185 ROME, ITALY
[4] UNIV LILLE 2, LAB APPLICAT SPECTROMETRIE MASSE, F-59045 LILLE, FRANCE
[5] UNIV PARIS 06, FAC MED ST ANTOINE, U402 INSERM, F-75571 PARIS, FRANCE