Proteomic

 

Nowadays we know that genome define the information content of organism and genome sequence has changes biology forever. However genome sequence does not tell how an organism works but it can tell by study protein, the functional molecules. The protein complement that expressed by genome or tissue is called Proteome. The word is derived from PROTEins and by genOME, since proteins are expressed by the genome. Proteomes are dynamic that change as a function of time, development, extracellular or intracellular condition. The proteome is larger than the genome, especially in eukaryotes, in the sense that there are more proteins than genes. This is due to alternative splicing of genes and post-translational modifications like glycosylation or phosphorylation.

Proteomic is the study of proteome that aim to separate, identify and characterize proteins on a large scale to define levels of protein in cells and tissues and how these change. Proteomic need to investigate protein complex because protein can operate by themselves or associate with other protein and need to elucidate protein function, pathways and the interrelationships of protein.

Protein separation Traditional protein chemistry use column chromatography, such as ion exchange or reversed phase chromatography, which can separate only one protein at a time and purification for a long time (month).The best tool available for separation of many proteins at once is 2–dimensional polyacyramide gel electrophoresis.

Protein identification and characterization Proteomic require high throughput, in previously protein have identified with Edman sequencing, antibody, amino acid composition or co-migration but now using mass spectrometry and peptide mass fingerprinting or peptide fragment.And now we have Automation of protein identification with high throughput including spot excision, trypsin digestion, MALDI target loading, spectra acquisition, calibration spectra, peak picking spectra and database matching. Automation such as protein excision robot, Automate Liquid Hading & Delivery, Automate Mass spectrometry.Because of peptide usually fragment at amide bonds between amino acids because masses of each peptide fragment can be calculated so peptide can be sequence and modification can also be localized to a single amino acid. To predict the modification on peptide that present the protein. We can use computer program “FindMod”.

Proteomic will define the proteome of a cell or tissue meaning what protein are express at what time and what condition, provide means of comparing proteomes to explain phenotype, provide clue to protein function by define co-stimulate and co-regulation protein and is potential in combination with other technology, but proteomic will not replace genome sequencing and can not be ease as genome sequence.