Figure 2 of
Takemoto, Mol Vis 5:2, 1999.
Figure 2. Quantitation of asparagine-101 deamidation
Resolution of amidated and deamidated forms of tryptic peptides corresponding to sequence 101-103 of [alpha]-A crystallin. The tryptic digest was resolved on a C8 reverse phase column (4.6 mm x 250 mm, Phenomenex) using a linear gradient of 0 - 10% (v/v) acetonitrile in 0.1% (v/v) trifluoroacetic acid over 27 min, followed by a linear gradient of 10 - 60% (v/v) acetonitrile in 0.1% (v/v) trifluoroacetic acid, over a period of 5 min. Only the part of the elution profile showing peptides of interest is shown. Top, digest from 71 yr old normal lens (71N); middle, digest from 65 yr old cataract lens (65C) with opacification of the nucleus; bottom, synthetic peptide standards (STND). Open arrows designate elution of amidated peptide HNER, closed arrows designate elution of deamidated peptide HDER.