Fig. 2
The serum peptidome data obtained from MALDI-TOF MS were used to screen peptide profiles and generate peptide mass fingerprints (PMFs) (A). The average mass spectra ranged from m/z 1,000 to 6,000. The upper panel displays spectra from Hepatozoon canis-infected dogs, while the lower panel represents healthy controls. The accompanying color scale indicates peptide concentration levels, with red representing higher and blue representing lower abundance (B). The Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) demonstrated clear separation between the infected and control groups (C). The volcano plot analysis revealed peptide masses with statistically significant differences (p < 0.05) and fold changes greater than 2.0 between the two groups (D). The Variable Importance in Projection (VIP) score analysis identified the top 40 candidate peptides, each with a VIP score exceeding 2.0, indicating their strong contribution to group differentiation based on MALDI-TOF MS data.
