Elaborate Manifold of Short Hydrogen Bond Arrays Mediating Binding of Active Site-Directed Serine Protease Inhibitors

IVGGYTCGANTVPYQVSLNSGYHFCGGSLINSQWVVSAAHCYKSGIQVRLGEDNINVVEGNEQFISASKSIVHPSYNSNT
LNNDIMLIKLKSAASLNSRVASISLPTSCASAGTQCLISGWGNTKSSGTSYPDVLKCLKAPILSDSSCKSAYPGQITSNM
FCAGYLEGGKDSCQGDSGGPVVCSGKLQGIVSWGSGCAQKNKPGVYTKVCNYVSWIKQTIASN

magnesium sulfate soak at target pH (5.65). vapor diffusion at 298 K, pH 8.10

Bovine trypsin complex with different inhibitor

Residues simultaneously refined in two or more conformations are: Leu66, Ser86, Lys87, Se113, Ser130, Lys159, Asp165, Ser170. Gln175, Ser217, Lys230, Ser236, Ser244.

OgSer195, HOH383, and O6' and N3 of the inhibitor form a 4-centered short hydrogen bond array.

His40 and HIS91 are MONOPROTONATED ON THE EPSILON NITROGEN. His57 is doubly protonated.

serine protease, short hydrogen bond, inhibition mechanism, shift of pKa, trypsin, thrombin, urokinase, factor Xa, hydrolase