contact george Wick , University of Innsbruck Austria, tel +43-512-507-3100, he is a leading expertz on that. best Lukas A. Huber OFFICE: Département de Biochimie Université de Genève, Sciences II 30, quai Ernest-Ansermet 1211 Genève 4 FAX: +41 22 702 6464 PH: +41 22 702 6467 (office), +41 22 702 6468 (lab) e-mail: LHUBER at sc2a.unige.ch