Fragments matching several proteins were obtained in the major spots at about 140 and 120 kDa, ie: dipeptidyl peptidase IV (DPPIV) and neprilysin (NEP) (140 kDa), and phosphodiesterase-I (E-NPP3) and beta-mannosidase (120 kDa). These proteins were also found when the 140 kDa and 120 kDa bands from a one-dimensional gel were processed in the same way.
Because of their abundance and the vertical smear they produced in the gel, dipeptidyl peptidase IV and neprilysin signatures were found in a large number of other spots with lower molecular weights. The cytoskeleton protein actin (45 kDa) was also one of the major proteins of the vesicles; this protein was separated as a series of at least four different spots composed of alpha- and beta-actin isoforms. The actin-associated protein Ezrin/Cytovillin was found in two major trains of spots: one at 75-80 kDa, which is its normal molecular weight, and one at 50 kDa, which could represent a degradation product of this protein. Tubulin and annexin II were two other cell-membrane cytoskeleton components identified.