FIGURE 5.

Superimposed ¹³C-HSQC spectra of the Ile, Leu, and Val methyl groups of CIB1 and CIB1 bound to αIIb in the absence (black) and in the presence of 6 eq of TEMPOL (red). The same amount of TEMPOL (6 eq) was added into ¹²C,²H,¹⁵N-uniformly and Ile-δ1-¹³CH₃,Leu,Val-¹³CH₃,¹²CD₃-labeled Ca²⁺-CIB1 (A) and Mg²⁺-CIB1 (B) samples at the same concentration (0.3 mm). The peaks marked with an asterisk are most likely from the ¹³C isotopic natural abundance of TEMPOL as those peaks do not appear for the protein alone.