Bangalore (ISJ). A trans-national team of scientists have decoded human ?proteome? or proteins in the human body, which could revolutionise medical research and diagnostics. The project led by researchers from Institute of Bioinformatics, Bangalore and The John Hopkins University, Maryland, USA, have identified proteins encoded by 17,294 genes, which is about 84 per cent of all genes in human genome. Of this, 193 proteins were considered to be non-existent so far by geneticists.
"You can think of the human body as a huge library, where each protein is a book,? said Dr. Akhilesh Pandey, professor at the MuKusick-Nathans Institute of Genetic Medicine at The Johns Hopkins University and the founder director of Institute of Bioinformatics. ?The difficulty is that we don?t have a comprehensive catalogue that gives us the titles of the available books and where to find them.?
?We are calling it draft map of the human proteome because we have only sampled a subset of tissues derived from few individuals. More work needs to be done to understand how protein profiles would vary between individuals and across populations,? added Dr. Harsha Gowda of Institute of Bioinformatics, Bangalore, one of the lead authors of the study, while talking to Indian Science Journal (ISJ).
The researchers took samples of 30 tissues, extracted its proteins and used enzymes like chemical scissors to cut them into smaller pieces, called peptides. The peptides were scanned through a series of instruments designed to deduce its identity and measure its relative quantity.
Dr. Pandey said, it is far more technically challenging to study proteins than genes, because the structures and functions of proteins are complex and diverse. While genes determine many of the characteristics of an organism, they do so by providing instructions for making proteins, the building blocks and workhorses of cells and therefore of tissues and organs. It is therefore, more useful to find their location within the body ? to be even more instructive and useful than the catalog of genes in the human genome.
The project is expected to be an important resource for biological research and medical diagnostics according to the team leaders.
?Most biomarkers used in medical diagnostics are proteins. For example, an increased level of a protein called troponin in blood is used as a biomarker for myocardial infarction (heart attack). Similarly, biomarker used in pregnancy strip test is a protein called human chorionic gonadotrophin (hCG). In that sense, knowing which proteins are produced where and under what circumstances can form the basis for medical diagnostics,? said Dr. Gowda.
?We observe that expression of some of the proteins is restricted to few organs in the human body. In diseases and pathological conditions that affect these organs, these proteins can be potentially useful for developing medical diagnostics. Even in cancers, a number of molecular markers used by pathologists are proteins. By providing a baseline map of human proteins across the human body, we have facilitated other researchers to investigate their potential utility in medical diagnostics for various disease conditions including cancers,? added Dr. Gowda.
Dr. Gowda said, they plan to build upon the present research outcome for a comprehensive data on protein profiling of Indian population, which has rich genetic diversity. ?Yes, we are already carrying out studies on tissues that were not sampled as part of our published study.? In addition, he said, the team is also doing research to determine how this protein profile changes in various disease conditions including neurological disorders and cancers affecting different organs in the human body.
By N.B. Nair
Part source: The John Hopkins University press release