Table 1.

Edman degradation analysis of early fragmentsa

FragmentN-Terminal Sequence
BandApproximate size (kD)LysosomesCathepsin D
122FVQGNFVQGN
2a9GSSHH
2b8.9FVQGNFVQGN
TSAGSIMFTSAGS
36(NL)(QVP)(NG)
nNVN
44.5(SML)(NAL)(NP)IMFTS
laLASLN
  • a The amino terminal sequences of the bands numbered in Figure 2 (two bands within band 2 were cut out separately, labeled 2a and 2b) were determined by Edman degradation after blotting onto polyvinylidene difluoride membranes. Clear sequences, shown in capital letters, uniquely identify the N-termini of α3(IV)NC1 fragments. Sequences that were identical for α3(IV)NC1 fragments in lysosomal and cathepsin D digests are shown in boldface. In the case of two samples more than one amino acid (shown in parentheses) was detected at each Edman cycle, indicating the presence of more than one peptide sequence. In both cases, the data were consistent with the presence of a fragment with N-terminal sequence (shown in lower case to reflect lack of absolute identification) that was identical to equivalent-sized bands that were released by cathepsin D digestion.