Table 1. Four Test Systems Used in This Work^a.

system	system volume (nm3)	no. atoms	sphere radius (Å)	sphere atoms (Cα)
water box	64.02	6282	none	none
HSP90	223.90	22446	6	Leu48, Gly97
trypsin	226.50	22681	6	Gly226, Ala221
MUP-I	210.37	21170	6	Lys55, Leu117

^aListed with the volume of each system, the number of atoms after equilibration (n.b. this may change during the simulation), the radius used to define the spherical region of interest for water insertion and deletion moves, and the backbone C_α atoms whose midpoint was used to define the center of the GCMC sphere (residue IDs as per the crystal structures).