Figure 9.
ESI-MS-MS of products obtained from Rce1p-catalyzed proteolysis of substrate peptides 2 and 4. (A) Farnesylated proteolysis product 7 (-f, loss of farnesyl (C15H25); -h, loss of H2O). (B) Benzophenone-modified proteolysis product 8 (BP, benzophenone fragment, (3-benzoylphenyl)methylium (C14H11O+); -b, loss of benzophenone fragment; -c, loss of (E)-(3-(((2-methylbut-2-en-1-yl)oxy)methyl)phenyl)(phenyl)methanone (C19H20O2); -d, loss of benzophenone-H2O, (3-(hydroxymethyl)phenyl)(phenyl)methanone (C14H13O2); -h, loss of H2O).