. Author manuscript; available in PMC: 2010 Jun 28.

Published in final edited form as: Biochemistry. 1995 Mar 7;34(9):3048–3055. doi: 10.1021/bi00009a036

Table 1.

Positions Chosen for Cysteine Substitution

cysteine substitutions	twist angle Θ_T^a (deg)	C^β–C^β distance r^β_ij^b (Å)	C^β solvent accessible surface area^c
M182C			37
M182C/Q26C	−80	(27.8)	37/47
M182C/D15C	−36	12.4	37/28
M182C/N13C	−27	12.3	37/80
M182C/N43C	0	8.9	37/50
M182C/A71C	40	15.9	37/88
M182C/S95C	62	21.1	37/63
M182CE240C		(18.4)	37/69

Hinge-twist angle, where the axis of rotation is defined in Figure 2 (see Results).

Distance between the β-carbons of the substituted positions. Values in parentheses indicate distances measured through the core of the protein, arising from a cysteine pair on opposite surfaces of the molecule.

For each substituted position the solvent-accessible surface area of the β-carbon was determined by first removing crystallographic waters and the distal atoms of the side chain. Subsequently the program ACCESS (Richards, 1977) was employed to calculate exposure to a 1.4 Å radius probe, with slab thickness 0.1 Å