The refined 1.9 A crystal structure of human alpha-thrombin: interaction 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,S.R.; Hofsteenge,J. (EMBO J, 1989)