Analysis of mutations exclusive to amyloidogenic derivatives. A rough analysis of mutation patterns could be made by dividing the matrix using the diagonal, or by dividing it into quadrants. Mutations to the right of the diagonal are characterized by increased sheet-forming propensities (+), while those to the left imply the opposite (-). In terms of the quadrants, which are numbered in the same way as the Cartesian plane, the first contains information on mutations from low- to mid-propensity, sheet-associated amino acids to relatively high-propensity sheet-associated amino acids (++), while the third quadrant contains the opposite (--). In the most general sense, mutations either on the right of the diagonal, or in the first and third quadrants (shaded), would be the biggest contributors to destabilization. The analysis indicates that a significant number of mutations in the exposed CDR residues result in increased β-sheet-forming propensities, while mutations in buried FR residues tend to be associated with a decrease in β-sheet-forming propensities.