[1] CNR, Ist Chim Riconoscimento Mol, I-20131 Milan, Italy
[2] Univ Milan, Dipartimento Biol, I-20134 Milan, Italy
[3] Univ Naples Federico 2, Dipartimento Chim Organ & Biochim, I-80126 Naples, Italy
[4] Univ Groningen, Mol Enzymol Grp, NL-9747 AG Groningen, Netherlands
[5] Catholic Univ Louvain, Bioengn Grp, Earth & Life Inst ELI, B-1348 Louvain, Belgium