As we enter a post-genomic era, it has become apparent that a significant number of the genes identified in bacterial genomes encode proteins of unknown function.\u00a0 The development and refinement of tools and techniques to elucidate the function of these poorly characterized proteins will be required.\u00a0 My research interests are in developing peptide-based tools to determine the role of various proteins of unknown function in bacterial metabolism and virulence.\u00a0 In addition, many of the genes encoding proteins of unknown function are required for cell viability.\u00a0 These essential genes represent valid targets for antibacterial drug discovery but are typically not accessible using standard biochemical assays.\u00a0 The peptide-based tools developed to ascribe function to these essential gene products can be readily converted into high throughput screening (HTS) assays for drug discovery.<\/p>\n
Over 700 bacterial genomes have been completely sequenced and at least an equal number are in progress.\u00a0 This work provides a large amount of genetic and genomic information; however, to extend the value of these data will require functional characterization of the gene products.\u00a0 Mycoplasma genitalium has one of the smallest genomes of any free-living organism.\u00a0 Characterization of the genes essential for M. genitalium viability has shown that 382 of the 482 M. genitalium protein-coding genes are essential. Of those 382 essential genes, 28% encode proteins of unknown function.<\/strong>\u00a0 To take full advantage of the bacterial genomic information available and to have a more complete understanding of the role these proteins of unknown function in bacterial physiology will require additional tools.\u00a0 High affinity binding reagents and inhibitors have traditionally been used as tools to characterize protein function.\u00a0 Peptide-based phage display technology offers a way to rapidly isolate such reagents.<\/p>\n Phage display is a powerful technology that my lab has used to identify peptides that bind to a wide range of targets from proteins to biomaterials.\u00a0 Combinatorial peptide libraries are constructed by inserting peptide-encoding oligonucleotides into gene III of bacteriophage M13.\u00a0 The resulting peptide fusions are displayed on the surface of the bacteriophage and can be screened for binding to a target of interest.\u00a0 When applied to protein targets, we have observed that the peptides are directed to functional sites on the protein and don\u2019t bind randomly to the protein.\u00a0 For an enzyme, this includes targeting the active site and the peptide will function as an inhibitor of the enzymatic activity, even if the enzymatic substrates are none peptidic in nature.\u00a0 For example, we have isolated peptides that bind to alcohol dehydrogenase and inhibit the conversion of ethanol to acetaldehyde with a Ki of 80 nM.<\/p>\n In addition to their use as inhibitors in biochemical reactions, peptides can be expressed inside cells to bind the target protein and disrupt its function.\u00a0 When applied to proteins that are essential for cell viability, this \u201cprotein knockout\u201d will result in inhibition of cell growth.\u00a0 We have validated this protein knockout approach with several essential bacterial proteins and want to apply it to proteins of unknown function that are identified by genomics.<\/p>\n Infectious diseases are still a leading cause of death worldwide.\u00a0 With increasing antibiotic resistance among bacterial pathogens and the emergence of hard-to-treat opportunistic infections, the need for new antibiotics continues.\u00a0 Among pharmaceutical companies, however, antibacterial research and development has been downsized or eliminated.\u00a0 Bacterial genomics has provided a large number of new targets for antibacterial drug discovery.\u00a0 As described above, a significant number of the essential genes identified by genomics encode proteins of unknown function.\u00a0 In previous work, we have shown that peptides isolated by phage display can be used as surrogate ligands to develop HTS-compatible assays to screen chemical compound collections for the discovery of new antibacterial agents.<\/p>\n My longer term goals include elucidating the role of proteins of unknown function in bacterial metabolism and virulence and developing small chemical molecules and peptides as research tools for characterization of bacterial proteins and enzymes.<\/p>\n","protected":false},"author":24,"featured_media":622,"template":"","meta":{"_acf_changed":false,"ncst_dynamicHeaderBlockName":"","ncst_dynamicHeaderData":"","ncst_content_audit_freq":"","ncst_content_audit_date":"","_links_to":"","_links_to_target":""},"group":[23],"person_tag":[],"class_list":["post-621","person","type-person","status-publish","has-post-thumbnail","hentry","group-emeriti"],"acf":[],"_links":{"self":[{"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/person\/621","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/person"}],"about":[{"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/types\/person"}],"author":[{"embeddable":true,"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/users\/24"}],"version-history":[{"count":6,"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/person\/621\/revisions"}],"predecessor-version":[{"id":2567,"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/person\/621\/revisions\/2567"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/media\/622"}],"wp:attachment":[{"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/media?parent=621"}],"wp:term":[{"taxonomy":"group","embeddable":true,"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/group?post=621"},{"taxonomy":"person_tag","embeddable":true,"href":"https:\/\/units.cals.ncsu.edu\/microbiology-graduate-program\/wp-json\/wp\/v2\/person_tag?post=621"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Antibacterial Drug Discovery<\/h3>\n