TABLE 1.

Identification of candidate tyrosine-sulfated proteins from the membrane fraction of mouse epididymis Candidate tyrosine-sulfated proteins from detergent extracts of the membrane fraction from wild type epididymis were enriched by affinity chromatography on a PSG2 mAb column. Proteins were electrophoresed on SDS-polyacrylamide gels, stained with colloidal Coomassie, then excised and subjected to in-gel tryptic digestion and MS/MS sequencing as described under “Experimental Procedures.” Proteins with transmembrane domains or lipid anchors are indicated by an asterisk.

Gene name	Protein	Lengtha	Coverage	Bandb
Fga	Fibrinogen, α chain	557	18%	1
Fgb	Fibrinogen, β chain	481	38%	1
Fgg	Fibrinogen, γ chain	436	25%	1
Golm1	Golgi membrane protein 1*	393	37%	2,3,4
Cd109	CD109 antigen*	1442	22%	2,3,4
Nid1	Nidogen 1	1245	9%	4
Hspa5	Heat shock protein 5	655	30%	5
Lum	Lumican	338	37%	5,6,7
Mfge8	Milk fat globule-EGF factor 8 protein	426	23%	6
Atpsb	ATP synthase, β subunit	529	19%	7

^aLength of polypeptide precursor

^bIndicates the gel band from which the protein was identified (see Fig. 8). For proteins identified in multiple bands, the bands yielding the best Mascot score are in underlined in bold