The refined 1.9 Å crystal structure of human α-thrombin: Interactions with D-Phe-Pro-Arg chloromethylketone and significance of the Tyr-Pro-Pro-Trp insertion segment - Bode, W; Mayr, I; Baumann, U; Huber, R; Stone, SR; Hofsteenge, J (EMBO J, 1989)