The key requirement in understanding protein function is to learn to correlate the vast array of potential protein modifications to particular phenotypic settings, and then determine if a particular post-translational modification is required for a function to occur
Tags: Proteins
Proteomics is the large-scale study of proteins, particularly their structures and functions.[1][2] Proteins are vital parts of living organisms, as they are the main components of the physiological metabolic pathways of cells. The term "proteomics" was coined to make an analogy with genomics, the study of the genes. The word "proteome" is a blend of "protein" and "genome". The proteome is the entire complement of proteins, including the modifications made to a particular set of proteins, produced by an organism or system. This will vary with time and distinct requirements, or stresses, that a cell or organism undergoes.
Proteomics is often considered the next step in the study of biological systems, after genomics. It is much more complicated than genomics, mostly because while an organism's genome is more or less constant, the proteome differs from cell to cell. This is because distinct genes are expressed in distinct cell types, meaning that even the basic set of proteins which are produced in a cell needs to be determined. In the past this was done by mRNA analysis, but it is now known that mRNA is not always translated into protein, and the amount of protein produced for a given amount
To list all the protein modifications that might be studied in a "Proteomics" project is to recapitulate a discussion of most of biochemistry; therefore for now a short list might help to illustrate the complexity of the problem. In addition to phosphorylation and ubiquitination, proteins can be subjected to methylation, acetylation, glycosylation, oxidation, nitrosylation, etc. Some proteins undergo ALL of these modifications, which nicely illustrates the potential complexity one has to deal with when studying protein structure and function.
Even if one is studying a particular cell type, that cell may make different sets of proteins at different times, or under different conditions. Furthermore, as mentioned, any one protein can undergo a wide range of post-translational modifications. Therefore a "proteomics" study can get quite complex very quickly, even if the object of the study is very restricted. In the more ambitious settings, such as when a biomarker for a tumor is sought - and thus the proteomics scientist is obliged to study sera samples from multiple cancer patients - the amount of complexity that must be dealt with is as
PMAP is to aid the protease researchers in reasoning about proteolytic networks and metabolic pathways.
Understanding the proteome, the structure and function of each protein and the complexities of protein-protein interactions will be critical for developing the most effective diagnostic techniques and disease treatments in the future. An interesting use of proteomics is using specific protein biomarkers to diagnose disease. A number of techniques allow to test for proteins produced during a particular disease, which helps to diagnose the disease quickly. Techniques include western blot, immunohistochemical staining, enzyme linked immunosorbent assay (ELISA) or mass spectrometry. The following are some of the diseases that have characteristic biomarkers that physicians can use for diagnosis.
Immunoproteomics is a term used to describe the study of large sets of proteins (proteomics) involved in the immune response. Examples of common applications of immunoproteomics include: the isolation and mass spectrometric identification of MHC (major histocompatibility complex) binding peptides purification and identification of protein antigens binding specific antibodies (or other affinity reagents), and comparative immunoproteomics to identify proteins and pathways modulated by a specific infectious organism, disease or toxin. The term proteomics also usually implies that mass spectrometry is the ultimate technique used for protein identification.
Scientists are very interested in proteomics because it gives a much better understanding of an organism than genomics. First, the level of transcription of a gene gives only a rough estimate of its level of expression into a protein. An mRNA produced in abundance may be degraded rapidly or translated inefficiently, resulting in a small amount of protein. Second, as mentioned above many proteins experience post-translational modifications that profoundly affect their activities; for example some proteins are not active until they become phosphorylated. Methods such as phosphoproteomics and glycoproteomics are used to study post-translational modifications. Third, many transcripts give rise
Many drugs control blood pressure by interfering with angiotensin or aldosterone. However, when these drugs are used chronically, the body increases renin production, which drives blood pressure up again. Therefore, doctors have been looking for a drug to inhibit renin directly. Aliskiren is the first drug to do so.[
In principle, channelomics uses most of technologies of biochemistry or proteomics, however, perhaps the most important technology almost uniquely developed for channelomics is the patch clamp branch of electrophysiology.
The main distinguishing feature between p90rsk and p70rsk is that the 90 kDa family contain two non-identical kinase domains, while the 70 kDa family contain only one kinase domain.
The rationale behind asparaginase is that it takes advantage of the fact that ALL leukemic cells are unable to synthesize the non-essential amino acid asparagine whereas normal cells are able to make their own asparagine.leukemic cells require high amount of asparagine. These leukemic cells depend on circulating asparagine. Asparaginase however catalyzes the conversion of L-asparagine to aspartic acid and ammonia. This deprives the leukemic cell of circulating asparagine.
Genomically, ADAMTS13 shares many properties with the 19 member ADAMTS family, all of which are characterised by a protease domain (the part that performs the protein hydrolysis), an adjacent disintegrin domain and one or more thrombospondin domains. ADAMTS13 in fact has eight thrombospondin domains. It has no hydrophobic transmembrane domain, and hence it not anchored in the cell membrane.[1]
Ubiquitin is a small protein that can be affixed to certain protein substrates by enzymes called E3 ubiquitin ligases. Determining which proteins are poly-ubiquitinated can be helpful in understanding how protein pathways are regulated. This is therefore an additional legitimate "proteomic" study. Similarly, once it is determined what substrates are ubiquitinated by each ligase, determining the set of ligases expressed in a particular cell type will be helpful.
Most proteins function in collaboration with other proteins, and one goal of proteomics is to identify which proteins interact. This is especially useful in determining potential partners in cell signaling cascades. Several methods are available to probe protein-protein interactions. The traditional method is yeast two-hybrid analysis. New methods include protein microarrays, immunoaffinity chromatography followed by mass spectrometry, and experimental methods such as phage display and computational methods.