Table 1.

The average exposure ratio accompanied by the standard deviation (SD) of seven transmembrane segments of the β₂AR in different conformational states

TM	3D4S (partial inverse agonist, timolol)	2RH1 (partial inverse agonist, carazolol)	3NYA (neutral antagonist, alprenolol)	3P0G (agonist)
TM1	0.6160 ± 0.3655	0.6666 ± 0.3538	0.6362 ± 0.3577	0.6550 ± 0.3419
TM2	0.3563 ± 0.3032	0.3629 ± 0.3012	0.3446 ± 0.3129	0.3612 ± 0.3209
TM3	0.3003 ± 0.2926	0.3127 ± 0.2967	0.2516 ± 0.3083	0.2921 ± 0.3290
TM4	0.6449 ± 0.3572	0.6312 ± 0.3559	0.6429 ± 0.3591	0.6119 ± 0.3589
TM5	0.5647 ± 0.3854	0.6047 ± 0.3693	0.5674 ± 0.3760	0.5960 ± 0.3813
TM6	0.4648 ± 0.2884	0.4878 ± 0.3017	0.4662 ± 0.3084	0.6238 ± 0.3395
TM7	0.5189 ± 0.3497	0.5092 ± 0.3401	0.4816 ± 0.3624	0.4579 ± 0.3577

*The SD is calculated over a helical structure which is characterized by a periodic exposure progression (alternation of buried and exposed residues) which consequently leads to relatively high SD values