Peptides from βPG identified in <i>Arabidopsis</i>, cannabis and maize.

<p>Peptides from βPG identified in <i>Arabidopsis</i>, cannabis and maize.</p

MS/MS spectrum of the precursor at m/z 1548.6924.

<p>The peptide was identified as SFNEGTDKFTGYGK from the Cannabis sativa polygalacturonase non-catalytic protein (NCBI EST database GI:156080210). The upper panel shows the MS/MS spectrum with y- and b-ions indicated respectively in red and green. The one-letter code is used for the amino acids and dF indicates a didehydrophenylalanine. The lower spectra illustrate the specificity of the modification. While no mass shift is observed for the Phe closest to the N-terminus, illustrated by the lack of secondary peak at 233 for the b2-ion shown in the left panel, the more C-terminal Phe is completely modified as illustrated for the y6- and b9-fragment in the central and right lower panel.</p

Identified peptides and sequence coverage for the contig 53836 (AGED database).

<p>The upper panel shows the identified peptides, mainly based on a database search of the dataset ft2011092714 (<a href="http://dx.doi.org/10.6084/m9.figshare.100494" target="_blank">http://dx.doi.org/10.6084/m9.figshare.100494</a>)[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0171990#pone.0171990.ref019" target="_blank">19</a>]. Peptides uniquely found in in-house datasets are indicated in red. The lower panel shows the translated contig, it contains two sequences coding for different βPG homologs. The signal- and propeptide (residue 1–110) as well as the two C-terminal BURP–domains are indicated in italics. The identified peptides are underlined and the repetitive tetrapeptide FxxY with modified phenylalanine in red. Those phenylalanine residues that were identified as not modified are indicated in blue. The proline that is reproducibly found to be oxidized is in green. Similar observations were done for other contigs.</p