Flexibility (Karplus-Schulz)

The Flexibility (Karplus-Schulz) track predicts backbone chain flexibility using the approach of Karplus and Schulz, 1985. The method is useful for resolving antigenic sites, as these regions tend to be among the most flexible in a polypeptide sequence.

To apply this track to the sequence:

In the Tracks panel, check the box next to Flexibility (Karplus-Schulz). The track will now be visible in the Analysis view

To edit track options:

Select the track in the Tracks panel. Open the Track Options section, which appears as follows:

• Flexibility threshold (0..2) – the value (between 0 and 2) where flexible residues are separated from rigid residues. In the default of 1, residues with Bnorm values below 1 are rigid and those above 1 are flexible. The most flexible residue is assigned a value of 2 and the least flexible is assigned 0.

Click if you wish to return to the default value.