Table 4.

Average number of atoms of a particular kind within a 3.5 Å radius of the polar atoms of the ionizable side chain.

Protein	Wata		Na+b	Nc		Od		Polare		Chargedf
	N	C	C	N	C	N	C	N	C	N	C
L25E	0.2	3.4	0	0	2.5	0.1	0	0	0	0	0
L38E	0.4	3.9	0	0.7	1.3	0.6	0	0.7	0.7	0	0
V66E	1.6	5.0	0	0	0.6	0.5	0.4	0	0	0	0.6
I72E	1.5	4.2	0.2	0.9	1.3	1.2	0.2	0	0.5	0	0
Y91E	1.7	4.2	0.8	0.2	0	0.3	0	1.3	1.1	0.1	0.5
I92E	1.1	4.9	0	0	0.5	0	0.2	0	0	0	0
Average E	1.1	4.3	0.2	0.3	1.0	0.9	0.1	0.3	0.4	0	0.2
V66D	0.4	5.9	0.4	1.0	0.1	0.8	0.8	0.2	0	0	0
I92D	1.1	5.9	0	0.8	0.7	0.4	0.2	0	0	0	0
Average D	0.8	5.9	0.2	0.9	0.4	0.6	0.5	0.1	0	0	0
L25K	0	3.4	0	0	0	0	0.6	0	0	0	0
L36K	0	1.9	0	0	0	0.6	1.4	0.5	0.3	0	0.4
L38K	1.7	1.6	0	0	0	0.9	1.2	0	0	0.2	1.0
T62K	1.0	1.8	0	0.3	0	1.1	2.5	0	0.4	0	0
V66K	0.5	3.0	0	0	0	0.4	0.7	0	0.6	0	0
I72K	1.7	3.7	0	0	0.2	1.2	0	0	0	0	0
I92K	0.6	1.9	0	0	0	0	1.5	0	0	0	0.2
L103K	0.6	1.1	0	0	0	0.4	1.0	0.6	1.7	0	0.3
V104K	0.5	3.0	0	0	0	0.9	0.2	0	0	0	1.2
L125K	0	2.9	0	0	0	0.7	0.4	0.2	0	0	0.5
Average K	0.7	2.4	0	0	0	0.6	1.0	0.1	0.3	0	0.4

^aWater oxygen atoms,

^bsodium ions,

^cbackbone nitrogen atoms (N),

^dbackbone oxygen atoms (O),

^eside chain polar atoms of any type,

^fside chain charged atoms of any type.

All numbers were obtained as an average over the last ns of simulations. Contributions smaller than 0.1 are not shown. N means neutral, and C means charged. For Glu, Asp and Lys side chains we show averages over all simulated side chains of a certain type (rows Average E, Average D and Average K respectively).