Fig. 4.

Schematic alignment of myosin heavy chains. A, Mapping of quantifiable myosin heavy chain (MyHC) peptides to their corresponding gene locus. Unique peptides used for quantification are indicated in black, non-unique peptides (not used for quantification) are marked in gray. Localization of phoshorylation sites are shown in red. B, MS spectra of representative SILAC peptide pairs derived from MyHC-1β, -IIa, -IIb, or MyHC-13 that show over- or underrepresentation in either soleus or EDL muscle. C, Example of a quantifiable peptide that is shared by various members of the MyHC1β family and that was therefore excluded from quantification.