Metabolomics is the study of metabolite profiles in biological samples, particularly urine, saliva and blood plasma; the total number of metabolites in the human is unknown: estimates range from 3000 to 30000
The study of global metabolite profile in cells, tissues and organisms. The metabolite profiles are typically generated with high throughput NMR spectroscopy and mass spectroscopy
These profiles are represented by analytical spectra, the metabolite profiles of different cellular condition are compared using statistical techniques like pattern recognition
Metabolic profiling, the elucidation of the small molecule components of a cell, tissue or organism, has emerged as a useful technique in such diverse fields as drug discovery, clinical diagnostics and plant biochemistry
Metabolome is a pattern of molecules that reflects the cell’s status. It is the totality of metabolic processes including anabolism and catabolism, as well as all the related cellular processes such as absorption, distribution, and detoxification of natural and xenobiotic materials, energy utilization, signal transduction, and regulation.
It results from the expression of the genome and proteome in response to the cellular environment. While the Genome is representative of what might be, and the Proteome is what is expressed, it is the Metabolome that represents the current status of the cell or tissue .
Is a series of consecutive enzymatic reactions that produce specific products
Their reactants, intermediates and products are referred to as metabolites.
Basic concepts of Metabolic pathways
Metabolic pathways are irreversible
Every pathway has a first committed step
All metabolic pathways are regulated
Metabolic pathways in Eukaryotic cells occur in specific cellular locations
Study of Metabolome - In terms of sequence of reactions by which a specific nutrients is converted to end products, and the energetics of these reaction. - In terms of the mechanisms by which each intermediate is converted to its successor. Such an analysis requires the isolation and characterization of the specific enzymes that catalyze the reactions - In terms of the control mechanisms that regulate the flow of metabolites through the pathway.
If only one enzyme-encoding gene out of a pathway of several steps is found in an annotated genome, it is likely to be a mistaken assignment.
Conversely, if all but one or two enzymes in a pathway have corresponding genes in the annotated genome, the missing steps are likely to be present amongst the unidentified genes and are worth hunting down.
Studying the metabolism of disease-causing organisms can also be an excellent means of identifying new drug targets.
Many pathogenic bacteria and parasitic eukaryotes are the subjects of ongoing genome sequencing projects.
If metabolic pathways can be identified which are essential in the pathogen but absent in the host, new drugs targeting the enzymes in these pathways are likely to be very effective.