Fig. 7.

Labeling trajectory for sperm fraction proteins. The incorporation of stable isotope labeled valine into 16 sperm proteins was assessed by LC-MS. For each protein, duplicate data at each time point reflect the RIA value obtained from epididymal preparations from two different mice; the entire curve is defined by the analysis of 10 individuals. The open and closed symbols reflect the two animals taken at each time point. For three proteins (TBB2, LDHC, and PTGDS), the data were obtained from two valine-containing peptides (circles and triangles). The proteins are serum albumin (ALBU), a kinase anchor protein 4 (AKAP4), CUB and zona pellucida like domain containing protein (CUDZ1), sperm-specific LDHC, prostaglandin H2 D isomerase (PTGDS), outer dense fiber protein 2 (ODFP2), fatty acid binding protein 9 (FABP9), epididymal specific lipocalin 5 (LCN5), testis-specific phosphoglycerate kinase (PGK2), tubulin β 2C (TBB2), voltage-dependent anion selective channel protein 2 (VDAC2), α-enolase (ENOA), glycerol-3-phosphate dehydrogenase (GPDM), phosphatidylethanolamine-binding protein 1 (PEBP1), cytoplasmic actin 1 (ACTB), and mitochondrial ATP synthase subunit α (ATPA). Kinetic analysis of the data is presented in supplemental Table 2b.