Protein Sequence Information and Features

Proteome refers to protein complement expressed by a genome. Thus proteomics concerns with the analysis of complete complements of proteins. It is the study of proteins that are encoded by the genes of a cell or an organism. Such study includes determination of protein expression, identification and quantification of proteins as well as characterization of protein structures, functions and interactions. The functional classification of proteins in genomes (i.e., proteomes) can be accessed from the Proteome Analysis Database at http //ebi.ac.uk/proteome/ (Apweiler et ah, 2001). 

The unique characteristic of each protein is the distinctive sequence of amino acid residues in its polypeptide chain. The amino acid sequence is the link between the genetic message in DNA and the three-dimensional structure that performs a protein s biological function. The sequence comparison among analogous proteins yields insights into the evolutionary relationships of proteins and protein function. 

The comparison of sequences between normal and mutant proteins provides invaluable information toward identification of critical residues involved in protein function as well as detection and treatment of diseases. The knowledge of amino acid sequences is essential to the protein s three-dimensional structure, mechanism of actions, and design. 

The general strategy for determining the amino acid sequence of a protein (Findley and Geisow, 1989 Needleman, 1975 Walsh et al., 1981) involves several steps  

Separation and purification of individual polypeptide chain from a protein containing subunits. 

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