[1] Boehringer Ingelheim RCV GmbH & Co KG, A-1221 Vienna, Austria
[2] Univ Dundee, Ctr Targeted Prot Degradat, Sch Life Sci, Dundee DD1 5JJ, Scotland
[3] Univ Dundee, Div Biol Chem & Drug Discovery, Sch Life Sci, James Black Ctr, Dundee DD1 5EH, Scotland
[4] Tech Univ Munich, Sch Life Sci, Prote & Bioanalyt, D-85354 Freising Weihenstephan, Germany
[5] Boehringer Ingelheim Pharmaceut, Ridgefield, CT 06877 USA