Fig. 5From: Investigation and identification of protein carbonylation sites based on position-specific amino acid composition and physicochemical featuresThe frequency differences of 20 × 20 amino acid pairs between carbonylated sites and non-carbonylated sites of lysine, arginine, threonine and proline. The amino acid pair with red box indicates an over-representation in carbonylated sites (positive data) comparing to non-carbonylated sites (negative data); on the other hand, green box means an under-representationBack to article page