Table 2.

Average packing values of amino acids in α-helices of membrane proteins^*

	1aij	6prc	1bcc	1be3	1bl8	2brd	1fum	1msl	1occ-α	1occ
Gly	0.533	0.541	0.553	0.497	0.431	0.459	0.533	0.607	0.567	0.534
Ala	0.548	0.519	0.438	0.410	0.500	0.448	0.456	0.421	0.477	0.485
Ser	0.522	0.519	0.465	0.445	0.533	0.398	0.443	0.493	0.491	0.484
Cys	0.613	0.495	0.573	0.470	0.294	—	0.590	—	—	0.478
Val	0.451	0.447	0.426	0.377	0.392	0.347	0.346	0.445	0.452	0.442
Thr	0.502	0.420	0.431	0.410	0.376	0.460	0.465	0.415	0.468	0.459
Asp	0.249	0.510	0.421	0.425	—	0.529	—	0.330	0.434	0.503
Asn	0.564	0.507	0.394	0.357	—	0.367	0.461	0.392	0.450	0.473
Leu	0.441	0.402	0.396	0.402	0.366	0.384	0.414	0.326	0.431	0.423
Ile	0.430	0.460	0.418	0.385	0.325	0.411	0.39	0.424	0.437	0.428
Lys	0.242	—	0.333	0.366	—	0.285	0.226	0.295	0.405	0.389
Arg	0.48	0.424	0.384	0.339	0.339	0.408	0.414	—	0.393	0.378
Glu	0.445	0.251	0.327	0.328	0.543	0.442	0.370	—	0.487	0.412
Gln	0.391	0.486	0.403	0.404	—	0.160	—	—	0.433	0.461
Met	0.538	0.524	0.409	0.406	0.550	0.510	0.471	—	0.422	0.438
Pro	0.527	0.570	0.439	0.404	—	0.515	0.381	—	0.489	0.512
His	0.551	0.459	0.429	0.416	—	—	0.399	—	0.484	0.453
Phe	0.407	0.444	0.429	0.407	0.337	0.393	0.433	0.309	0.447	0.44
Tyr	0.377	0.381	0.451	0.419	0.322	0.427	0.360	0.261	0.485	0.402
Trp	0.447	0.450	0.480	0.397	—	0.436	0.384	—	0.429	0.432
Average	0.469	0.469	0.427	0.408	0.417	0.413	0.412	0.389	0.461	0.451

^*The occluded surface calculations were carried out on full protein structures, but the packing values reported represent the helical residues only.