Dissection of Factors Affecting the Variability of the Peptide Bond Geometry and Planarity
Table 5
Average values (°) of the bond angles NCαC, NCαCβ, CβCαC, CαCO, CαCN+1, OCN+1, and C−1NCα for each amino acid residue type in α-helix in the 3° × 3° box centered at (ϕ, ψ) = (−63°, −43°).
Residue
Occurrence
NCαC
NCαCβ
CβCαC
CαCO
CαCN+1
OCN+1
C−1NCα
Ala
2036
111.0
110.4
110.6
120.6
116.8
122.5
120.8
Leu
1434
111.1
110.6
110.5
120.5
117.0
122.4
120.6
Met
272
111.1
110.7
110.5
120.5
117.0
122.5
120.6
Ile
830
110.5
110.9
111.3
120.6
117.0
122.4
120.7
Val
851
110.4
111.1
111.2
120.6
117.1
122.3
120.6
Cys
122
111.0
110.6
110.3
120.4
117.0
122.5
120.6
Asn
294
111.3
110.6
110.3
120.7
116.8
122.5
120.4
Gln
650
111.1
110.6
110.4
120.5
116.9
122.5
120.6
Ser
429
111.2
110.3
110.3
120.6
116.8
122.5
120.7
Thr
491
110.8
110.4
110.9
120.6
116.9
122.5
120.8
Phe
350
110.8
110.5
110.4
120.7
116.9
122.4
120.4
Trp
183
111.0
110.3
110.8
120.7
117.0
122.3
120.7
Tyr
299
110.9
110.3
110.4
120.5
116.9
122.5
120.7
Asp
559
110.9
110.8
109.8
120.7
116.8
122.5
120.6
Glu
1002
111.1
110.5
110.4
120.6
116.8
122.5
120.7
His
208
111.3
110.4
110.3
120.7
116.8
122.5
120.4
Lys
798
110.8
110.6
110.5
120.6
116.9
122.4
120.7
Arg
746
111.0
110.7
110.3
120.6
116.9
122.5
120.5
Gly
459
112.1
—
—
120.8
116.6
122.5
120.7
28
113.5
103.3
111.7
119.8
117.8
122.3
117.7
number of observations for Pro residues is very limited.
