Proteomics - Biomedical Informatics in Translational Research - page 85

CHAPTER 6
Proteomics

V. S. Kumar Kolli

6.1 Introduction

Proteins are ubiquitous in nature and are fundamental to life. They are the molecu-
lar machines that perform a multitude of functions critical to the cell. The expres-
sion of proteins in a cell is dynamic and changes over time and with the
physiological state of a cell. There is a great deal of interest in cataloging the
changes in protein expression with respect to changing physiological conditions and
external stimuli. Knowledge of the patterns of protein expression associated with a
biological state and changes in the biological state will lead to an understanding of
how proteins communicate with each other in transforming the information
through the dynamic networks that they build by associating into multiprotein
complexes. These are organized into pathways and they respond to changing condi-
tions and perform vital functions at the cellular level and also regulate gene
expression.
Alterations in the protein expression and structure will cause interruptions in
the normal intercellular communication and lead to abnormal (diseased) pheno-
types. Display of such alterations in the proteome requires high-throughput com-
prehensive protein separation and protein identification tools. This chapter
provides readers with an overview of how information pertaining to proteins is col-
lected from clinical samples and how this molecular information may be translated
into knowledge that can improve the health and outcomes of patients with
debilitating diseases.
Techniques for sequencing proteins were developed well before the develop-
ment of DNA sequence analysis, and the first biopolymer to be completely
sequenced was a protein, insulin [1]. This molecule had been the trendsetter in the
20th century for the advancement of sequence analysis technology and biotechnol-
ogy. Insulin, as the first therapeutic protein, laid the foundation for the development
of protein databases. A proposal to catalog all human proteins and determine their
location, concentration, structure, and interacting partners was debated in the early
1980s utilizing the then recently developed two-dimensional gel electrophoresis
technique (2DGE). The plan was never implemented, partly for political reasons,
and because of the lack of mature, sensitive technology for identifying the proteins

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