The dimeric transmembrane domain of prolyl dipeptidase DPP-IV contributes to its quaternary structure and enzymatic activities - Chung, K M; Cheng, J H; Suen, C S; Huang, C H; Tsai, C H; Huang, L H; Chen, Y R; Wang, A H; Jiaang, W T; Hwang, M J; Chen, X (Protein Sci, 2010)