Table 2. Cavity characteristics as measured or calculated by the program SiteMap for the cavity flanking β-sheet A .

SiteMap output values are given for volume (Vol.), exposure (Exp.), van der Waals contacts (Contact), hydrophobicity (Phob.), hydrophilicity (Phil.) and the weighted balance of these characteristics (Bal.) and also for hydrogen-bond donor/acceptor ratio (Don/Acc). Overall scores and those for the general ligand (SiteScore) and drug-like compound (Dscore) binding characteristics are also shown. ‘Tight binders’ refers to values derived from observed correlation with or deliberate calibration against a database of binding sites and ligand interactions characterized in vitro (Halgren, 2009 ▶). N/C, not calibrated by these studies.

Structure	Size (No. of site points)	Vol. (Å3)	Exp.	Enc.	Contact	Phob.	Phil.	Bal.	Don/Acc	SiteScore	Dscore
1qlp	123	252	0.606	0.709	0.908	0.713	1.033	0.691	0.714	1.009	1.029
2qug	78	183	0.639	0.703	0.905	0.557	0.943	0.591	0.967	0.937	0.945
3ne4	90	162	0.583	0.726	0.861	1.028	0.843	1.219	1.056	1.019	1.052
‘Tight binders’	N/C	N/C	≤0.49	≥0.78	Mean 1.0	Mean 1.0	Mean 1.0	Mean 1.6	N/C	≥0.8	Sub-µMKd correlates with ≥1.01