Short (< 4.5 A) Sequential and Medium-Range 1H-1H Distances in Polypeptide Secondary Structures
 
Distance
a-helix
310-helix
b
bp
turn Ia
turn IIa
daN
3.5
3.4
2.2
2.2
3.4
2.2
daN(i,i+2)
4.4
3.8
   
3.6
3.3
daN(i,i+3)
3.4
3.3
   
3.1-4.2
3.8-4.7
daN(i,i+4)
4.2
dNN
2.8
2.6
4.3
4.2
2.6
4.5
dNN(i,i+2)
4.2
4.1
   
3.8
4.3
dbN
2.5-4.1
2.9-4.4
3.2-4.5
3.7-4.7
2.9,4.4
3.6,4.6
dab(i,i+3)b
2.5-4.4
3.1-5.1
aThe two numbers refer to the distance between residues 2 an 3 and 3 and 4.  The range for daN(i,i+3) distances are for y1 varied between -180 and 180.
bRanges correspond to the distances of a b-methine proton is c1 is varied between -180 and 180.