FIGURE 2.

Multiple DPP bands are not due to variable levels of phosphorylation or glycosylation. A, DPP in large scale preparations (from 8 pigs) typically shows 2 prominent bands and 1 or 2 additional faint bands (lane 1). Dephosphorylation with acid phosphatase shifts the multiple bands down the gel, but the pattern of multiple bands is preserved. B, N-deglycosylation of the dephosphorylated DPP with glycopeptidase A (lane 2) does not significantly alter the mobility of DPP or its pattern of multiple bands (lane 1). C, O-deglycosylation of dephosphorylated and N-deglycosylated DPP (lane 2) does not significantly alter the mobility of DPP or its pattern of multiple bands (lane 1). The 3 DPP bands from lane 1 in panel A were excised from the gel and characterized by N-terminal sequencing. All gave the same result: DDPNS, which is the conserved DPP N-terminal sequence.