it is a student presentation and not so good but useful for other students around the world.

1. 5
Proteomics to study
genes and genomes
compiler: Yashgin Hassanzadeh

2. Introduction
o
Large-scale DNA sequencing has transformed biomedical
research in a short span of time. With the discovery of most
human genes, it is now apparent that a ‘factory approach’
to address biological problems is desirable if we are to gain
a comprehensive understanding of complex biological
processes. In this seminar we will review how proteomics is
similarly making a crucial contribution to our understanding
of biology and medicine through the global analysis of gene
products.

3. Defining proteomics
Large-scale study of proteins, usually by biochemical methods.
It is dates back to the late 1970s.
In 1990s, biological mass spectrometry emerged as a powerful
analytical method that removed most of the limitation of
protein analysis.
Today, the term proteomics covers much of the functional
analysis of gene products, including large-scale identification or
localization studies of proteins.

4. Why is proteomics necessary?
With the accumulation of vast amounts of DNA sequences in databases,
researchers are realizing that merely having complete sequences of genomes
is not sufficient to elucidate biological function.
There is no strict linear relationship between genes and the protein
complement. ORF in genomic data does not necessarily imply the existence
of a functional gene so it is still difficult to predict genes accurately from
genomic data.
Modification of proteins such as isoforms and post-translational
modifications, can be determined only by proteomic methodologies. The
localization of gene products, which is difficult to predict from the sequence,
can be determined experimentally and so on.

5. Identification and analysis of proteins
Protein preparation methods
Mass spectrometric identification of proteins
Post –translational modifications

6. Figure 1. A strategy for mass spectrometric identification of proteins and post-
translational modification.(Akhilesh Pandey and Matthias Mann)

7. Differential-display proteomics
The two-dimensional gel approach
Protein chips
Figure 2.
A
schematic
showing
the two-
dimensio
nal gel
approach.
(Akhilesh
Pandey and
Matthias
Mann)

8. Figure 3. A schematic showing
use of arrays for proteomics
analysis.

9. Protein-protein interactions
Purification of protein complexes
Yeast two-hybrid system
Figure 4. A schematic
strategy to isolate
interacting proteins.

10. Figure 5. The yeast two-hybrid
system.

11. Questions
• What is mass spectrometry method?
• Why we use peptides instead of proteins in MALDI?
• Why we use SDS-page in second steps of electrophoresis?
• What is the name of staining method for electrophoresis
gel?
• Why we should study proteomics?

12. Reference
Pandey, A. ,Mann, M. (2000). Proteomics to study genes
and genomes. Nature 405: 837-846.
Thank you