PNNL

Abstract

Proteomics is a relatively new scientific discipline dedicated to the comprehensive study of the protein composition of biological systems. While genomic sequencing is an invaluable tool for bioforensic sample identification, proteomics complements genomics in that the genes present in an organism code for the proteins that can be present in a microorganism. Many proteins are conserved for general identification while other protein expression varies with environment/growth state/growth conditions (i.e. not all proteins are expressed at any given time or condition) providing additional information beyond genomic analysis. This expression specificity and the relative stability of proteins with respect to genetic material make them attractive targets for microorganism identification and forensic applications to complement genomic approaches. Proteomic analysis depends upon the availability of genome sequences of the relevant organisms or their near relatives. The known amino acid sequences for potential proteins within the database can be compared to amino acid sequences of actual proteins present in a sample as determined with high mass accuracy by mass spectrometry for identification of the proteins in the sample. With the development of technology for rapid genome sequencing of organisms, the known protein database is growing, supporting improved identification of the proteins present in a sample. Recent developments in mass spectrometry instrumentation and microbial sequencing are leading to an increased growth in application of proteomics to microbiology, pathogen detection, disease diagnosis and microbial forensics as well as other biological disciplines. Mass spectrometry analysis does not require a priori knowledge of the sample or expected targets to gain meaningful.