Figure 5.
Correlation of protein abundances estimated by APEX vs. 2-DE based on hydropathy score. Hydropathy (GRAVY) score of a protein was calculated as the arithmetic mean of the sum of the hydropathic indices of each amino acid. The left end of the scale in Fig. 5a represents hydrophilic proteins, and the right end of the scale represents hydrophobic proteins. Within a particular hydropathy range, the number of proteins quantitated by APEX and 2-DE were compared against all protens predicted for Sd197. Correlation of protein abundances estimated by APEX vs. 2-DE decreased for very hydrophobic (R2 = 0.61) and also for very hydrophilic proteins (R2 = 0.52) compared to the overall abundance correlation.