Fig. 5.

Comparison of human and mouse vesicular and postsynaptic density fractions. A and B, depict representative chromatographic peaks of light and heavy peptides from four peptides with different expression values. Note that the y axis is log10. This figure highlights the similarity in relative protein expression between the standard and analyte proteomes. C–F, Human total homogenate fraction was mixed with the [¹³C₆]brain ISTD in the following ratios (μg): 1/19, 3/17. 10/10, 17/3, and 19/1. These preparations were analyzed by LC-SRM/MS in duplicate and the prepared L/H ratio plotted against the observed average L/H peptide ratio (peptide measure) for each protein. This figure show's representative curves for CaMKIIα, CDK5, NR1, and PSD95. The 19/1 point is not shown to highlight the midrange of the curve, but does not deviate from the slope reported here.