Biology Reference
In-Depth Information
Chapter 9
Plant Proteomics Methods to Reach Low-Abundance Proteins
Egisto Boschetti and Pier Giorgio Righetti
Abstract
The question of low-abundance proteins from biological tissues is still a major issue. Technologies have
been devised to improve the situation and in the last few years a method based on solid-phase combinato-
rial peptide ligand libraries has been extensively applied to animal extracts. This method has also been
extended to plant extracts taking advantage of fi ndings from previous experience. Detailed methods are
described and their pertinence highlighted according to various situations of plant sample origin, size of
the sample, and analytical methods intended to be used for protein identifi cations.
Key words
Low-abundance proteins, Combinatorial peptide ligand libraries, Protein depletion,
Protein fractionation
Abbreviations
CPLL Combinatorial Peptide Ligand Library
TUC
Thiourea-Urea-CHAPS
1
Introduction
Plant proteomics is experiencing a fast growth in present days and
is now well accepted by all dedicated proteomics journals. However,
there are still some major shortcomings that hamper proper discov-
eries in the fi eld [
1
-
3
]. One of them is the paucity of data on the
various genomes. It is thus clear that for further progress we need
the help of geneticists willing to tackle the sequencing of more and
more plant genomes (most of the papers published so far deal with
the proteomes of
Arabidopsis thaliana
and rice,
Oryza sativa
, and
focus on profi ling organs, tissues, cells, or subcellular proteomes).
The other major drawback is that in some tissues (like leaves) a few
proteins dominate the landscape and hamper proper discovery of
low-abundance species. This is further aggravated by the presence
