User:Mdilmir melb

For the journal Proteomics, see Proteomics (journal).

Proteomics is the study of protein structures and functions. Proteins can be chemically modified in different ways after synthesis and they are essential parts of living organisms. In Cancer Research, scientist believes that Proteomics is a fast growing science and it provides support in cancer diagnosis and further in treatment as well. Although, there are many known potential difficulties where the sensitivity, specificity, and reproducibility of the available molecular markers are unsatisfactory and do not match the expectations. But scientist still believe that with the improvement and advancement of proteomics technology, early diagnosis and treatment of cancer will be efficient and reliable in future. The human genome consists of complete set of genes that is required to build a functional human being. But the genome is just a source of information. In other words it is just a raw information and in order to function this information, it must be expressed in protein. The very first stage of gene expression is the transcription of genes and later it is followed by the translation of messenger RNA to actually produce proteins. The term proteome basically describes the entire set of proteins expressed by a given genome, cell, tissue, or organism at any one time. The complexity of proteome is much more higher than either the genome or the transcriptome. The reason of this is very simple, As each protein can be chemically modified in different ways after synthesis depending on its structrue and the way it folds. Most proteins have carbohydrate groups added to them. Some proteins have phosphorylated or acetylated or methylated groups added to them. The functions of the protein is totally dependent on the folded structure and the folded shape or structure of a proteins specified by its amino acid sequence. At cellular level, most of our cells have the same genome despite of the cell type, developmental stage or environmental conditions. But the proteome,being very dynamic, usually differs significantly in these differing circumstances and conditions. It can be due to different gene expression patterns or it can be different protein modification patterns.

The study of proteom gives a better understanding of an organism than genomics. In a cell, proteins represent the actual functional molecules. The changes that happens at the DNA level, it affects the proteins. e.g. if mutations occur in the DNA, it is the proteins that are eventually affected. Same in case of Drugs, when they have favorable effects, they do so by having an interaction with proteins.

Proteomics covers different aspects of protein function, It includes the following:

Structural proteomics, it includes the analysis of protein structures at large-scale. Where protein structure are compared and it helps to identify the functions of those genes which are newly discovered. The structural analysis also helps to understand that where drugs bind to proteins and also show where proteins interact with each other. This understanding is achieved using different technologies such as X-ray crystallography and NMR spectroscopy.

Expression proteomics, includes the analysis of protein expression at larger scale. Where it helps to identify the main proteins that are found in a particular sample and those proteins which are differentially expressed in related samples, such as diseased vs healthy tissue. If a protein is found only in a diseased sample then it can be a useful drug target or diagnostic marker. Proteins with same or similar expression profiles may also be functionally related. There are technologies such as 2D-PAGE and mass spectrometry that are used in expression proteomics.

Interaction proteomics, is the analysis of protein interactions at larger scale. The characterization of protein-protein interactions are useful to determine the protein functions and it also explains the way proteins assemble in bigger complexes. There are technologies such as affinity purification, mass spectrometry and the yeast two-hybrid system which are particularly useful in interaction proteomics.

The proteome analysis techniques are not simple and straightforward as those which are used in transcriptomics. But the benefit of proteomics is that it deals with the real functional molecules of the cells. It is known that Strong gene expression results in an abundant mRNA but it does not necessarily mean that the corresponding protein is also abundant.

Medical Definition

It is the branch of biotechnology which deals with applying the techniques of molecular biology, biochemistry and genetics to analyze the structure, functions and interactions of the proteins produced by genes of particular cell or tissue with organizing the information in databases and with applications of data.(2)

Introduction

Proteomics which is the study of complete complement of proteins will have major impact on all aspects of life sciences in the near decade. To understand biological processes, its a certainty to understand how proteins function in and around cells since they are the functioning units.

Proteomics and System Biology

Proteomics has recently come into the act as a promising force to transform biology and medicine. It is becoming increasingly apparent that changes in mRNA expression correlate poorly with protein expression changes. Proteins changes enormously in patterns of expressions across developmental and physiological responses. Proteins also face changes on the act of environmental perturbations. Proteins are the actual effectors driving cell behavior. The field of proteomics strives to characterize protein structure and function, protein-protein,protein-nucleic acid, protein-lipid, and enzyme-substrate interactions, protein processing and folding, protein activation, cellular and sub-cellular localization, protein turnover and synthesis rates, and even promoter usage. Integrating proteomic data with information such as gene, mRNA and metabolic profiles helps in better understanding of how the system works.

Current Proteomic Technologies

Proteomics has gained steady momentum over the past decade with the evolution of several approaches, few which are new and the others, which builds on traditional methods. Mass spectrometry based methods and Micro arrays are the most commonly used technologies for the large-scale study of the proteins.

Mass Spectrometry and Protein Profiling

Robotic preparation of MALDI mass spectrometry samples on a sample carrier.

Mass spectrometry

References

(1) http://www.proteomic.org/html/proteomics_.html (2)http://www.merriam-webster.com/dictionary/proteomics.html (3)http://archive.cspo.org/outreach/md/docs/Weston-Systemsbiology.pdf