Table 4.

Crystallized GASPIDs

GASPID	References	Special Features
Rat mast cell protease II + inhibitor	[79, 80]	Deep, extended substrate binding pocket
Human chymase + inhibitor	[81, 82]	High density of surface charge explains high affinity for proteoglycan
Human pro-chymase	[28]	Changes in active site conformation explain inactivity of pro-enzyme
Human cathepsin G + inhibitor	[86]	Active site mutations explain unusually broad specificity
Human β-tryptase + inhibitor	[54]	Toroidal, self-compartmentalizing tetramer; structure explains heparin stabilization
Human α-tryptase	[19]	Tetramer, with contorted, self-blocked active site
Human neutrophil elastase + inhibitor	[85]	Asymmetry of charge distribution explains proteoglycan binding
Rat Granzyme B + inhibitor	[87]	Structure explains unusual Asp specificity
Human Granzyme B	[142]	Structure explains unusual Asp specificity
Human granzyme A + inhibitor	[56, 57]	Dimer extends & protects active site
Human pro-granzyme K	[88]	Rigid, non-productive active site
Human Factor D	[52, 53]	Auto-blocked active site