Figure 8.

Size-exclusion chromatography of tetrameric WT, dimeric I99C/Y75A/Y37bA, and monomeric I99C*/Y75A/Y37bA β-tryptases in the presence or absence of heparin. After pro-domain removal by EK, proteins were analyzed on an S200GL column in either SEC buffer (without heparin) or in TNH buffer (with heparin). Elution volumes for WT tetramer without heparin (13.0 ml), I99C/Y75A/Y37bA dimer with heparin (14.1 ml), I99C/Y75A/Y37bA dimer without heparin (14.6 ml), I99C*/Y75A/Y37bA monomer with heparin (15.8 ml), and I99C*/Y75A/Y37bA monomer without heparin (16.3 ml) are as indicated in parentheses.