Short Notes on Proteomics | Biotechnology

The below mentioned provides a short note on proteomics.

The entire protein component of a given organism is called ‘proteome’, the term coined by Wasinger in 1995. A proteome is a quantitatively expressed protein of a genome that provides information on the gene products that are translated, amount of products and any post translational modifications.

Proteomics is an emerging area of research in the post-genomic era, which involves identifying the structures and functions of all proteins of a proteome. It is sometimes also treated as structural based functional genomics.

Methods of Proteome Analysis:

Resolution and identification of proteins are possi­ble by 2D-PAGE (Polyacrylamide Gel Electrophoresis) and Mass Spectrometry; compa­rative 2-D gel approach or protein chip approach helps to identify the proteins in up or down regulated system.

A variety of other techniques are used for protein identification, the most common being matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The hybrid electrospray ionization (ESI) method of quadrupole TOF-MS with its increased mass accuracy is becoming increasingly esta­blished.

Scope of Proteomics:

Proteomics deals with significant problems like:

(a) Identification of functional domains in protein sequences.

(b) Single, multiple protein alignment (homology).

(c) Determining sequence-structure, sequence function relationships (structural bio- informatics).

(d) Discovery of protein pattern and providing the framework for the analysis of signalling networks.

Reverse Genetics:

The research in proteomics has made it possible to get the know­ledge of all the proteins produced in an organism which may or may not be directly responsible for any phenotypic trait, but this may be helpful to know the functions of all the genes in that organism. This has made the approach of reverse genetics feasible because from the study of proteins, one can deduce the function of gene and the trait.

Significance of Proteomics:

The knowledge of proteomics is complementary to genomics and has become a major thrust area of genetics, molecular biology and biotech­nology research. From the whole genome sequence, functional genes are identified as open reading frames (ORFs) having initiation and termination codon, but ORF always does not represent any functional gene.

Verification of gene product by proteome analysis serves a very useful purpose for ‘annotation of the genome’. Post translational modification and expression of proteins, functions—all are regulated by various activities of the cellular metabolism—but all these are also due to proteolysis or protein-protein interactions.

Yeast Proteome:

The complete sequence of the whole genome of yeast has been worked out in 1996, nearly 6200 genes are present in this small organism. In 2001, the functions of 93% of the proteins (5800 proteins) encoded in the genes were also elucidat­ed.

Later (2002-2005) networks involving the interactions have also been studied. Study of yeast proteome in great details will be very useful for the study of functions of genes of higher organisms including human, since yeast is the simplest eukaryote.