%0 Journal Article %T An engineered lipocalin specific for CTLA-4 reveals a combining site with structural and conformational features similar to antibodies %A Schönfeld, D. %A Matschiner, G. %A Chatwell, L. %A Trentmann, S. %A Gille, H. %A Hülsmeyer, M. %A Brown, N. %A Kaye, P. M. %A Schlehuber, S. %A Hohlbaum, A. M. %A Skerra, A. %A , %J Proceedings of the National Academy of Sciences %@ 0027-8424 %D 2009-05-19 %I Proceedings of the National Academy of Sciences %~ DeepDyve