Carborane-Based Carbonic Anhydrase Inhibitors: Insight into CAII/CAIX Specificity from a High-Resolution Crystal Structure, Modeling, and Quantum Chemical Calculations

Table 4

Interactions between CAIX and 1.

CAIX			1
Residue		Atom	Atom^a	Distance [Å]^b
	Zn	ZN	N2	2.1
	Zn	ZN	S	3.3
	Zn	ZN	O2	3.5
5	Trp	CZ2	B5	3.74
5	Trp	CZ2	B10	3.81
94	His	CE1	O2	3.15
94	His	CE1	C3	3.74
94	His	NE2	N2	3.36
94	His	NE2	S	3.88
94	His	NE2	O2	3.45
94	His	NE2	C3	3.76
96	His	CE1	N2	3.99
96	His	NE2	N2	3.49
106	Glu	OE2	N2	3.71
119	His	ND1	N2	3.37
119	His	CE1	N2	3.83
121	Val	CG2	O2	3.58
198	Leu	CA	O1	3.04
198	Leu	CB	O1	3.4
198	Leu	CD2	O1	3.43
198	Leu	C	O1	3.38
199	Thr	N	S	3.88
199	Thr	N	O1	2.79
199	Thr	CA	O1	3.96
199	Thr	CB	N2	3.85
199	Thr	OG1	N2	2.63
199	Thr	OG1	S	3.69
199	Thr	OG1	O1	3.65
200	Thr	OG1	C1	3.77
200	Thr	OG1	B5	3.56
200	Thr	OG1	N1	3.13
200	Thr	OG1	C3	3.31
200	Thr	OG1	B4	3.64
201	Pro	O	B4	3.6
201	Pro	O	B10	3.49
201	Pro	O	B8	3.96
209	Trp	CZ2	O1	3.74

Atom labels correspond to those shown in Figure 1(a).
^bAll contacts with a distance less than or equal to 4 Å between ligand and protein (and Zn) atoms are listed.
^cPolar interactions are highlighted in bold.