Fig. 4
MWCNT-responsive thrombospondin fragment identified with CD36-modulatory motifs. a Among the identified peptides was a 59-mer thrombospondin fragment overlaping the second type-1 repeat domain (TSP402–460). Three established CD36 binding and modulatory motifs are color-coded and shown in bold within the peptide sequence. Matched mass spectral ion fragmentation sites are shown along the 59-mer sequence with a line angled to the left denoting a b-ion (left-to-right) a line angled to the right denoting a y-ion (right-to-left). b The TSP402–460 peptide’s corresponding fragment ion mass spectrum with peaks labeled for their reduced mass (MH+) and b/y-ion designation. c Mass spectral ion intensity for the TSP402–460 peptide plotted as mean ± SE, n = 6 matched serum and BALF specimens from replicate mouse exposures per dose, *p < 0.05. d Proteolytic processing map for known thrombospondin cleavage sites with the protease and site given relative to functional domains