Figure 4.
Fig. 4. Solvent-accessible molecular surface of PYP in (A)
the dark state and (C) bleached state color-coded for
electrostatic^ potential as calculated by DelPhi (29) (deep red,
< 4 kT;
white, neutral; dark blue, >4 kT). Partial charges were assigned
according to a revised version of the CHARMM force field (30).
In (B), C[ ]traces
and side chains of Arg52 for the dark (yellow) and bleached
(white) states are shown. Bleaching increases the positive
electrostatic potential at the^ active site. Movements of Arg52
and the chromophore change the surface shape.
The above figure is reprinted
by permission from the AAAs:
Science
(1997,
275,
1471-1475)
copyright 1997.
4 kT;
white, neutral; dark blue, >4 kT). Partial charges were assigned
according to a revised version of the CHARMM force field (30).
In (B), C[ 
]traces
and side chains of Arg52 for the dark (yellow) and bleached
(white) states are shown. Bleaching increases the positive
electrostatic potential at the^ active site. Movements of Arg52
and the chromophore change the surface shape.