Bacterial resistance to antibiotics has seriously limited our capacity to overcome infectious disease. Cases of resistance have emerged in virtually all hospital-acquired pathogen-antimicrobial combinations. Soon our most serious infectious threats will be untreatable given our dwindling arsenal of effective antibiotics. Ramoplanins and Enduracidins comprise a family of peptide antibiotics with potent broad-spectrum activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium (VRE), and cephalosporin-resistant Streptococcus pneumonia, three important opportunistic human pathogens. Ramoplanin and Enduracidin inhibit the transglycosylation cross-linking step of bacterial peptidoglycan biosynthesis in a complex mechanism involving capture of the transglycosylase substrate, Lipid Intermediate II.
In Aim 1 we seek to determine the molecular mechanisms of a recently identified secondary mechanism of Ramoplanin, inhibition of cell wall protein anchoring and biofilm development in Gram-positive bacteria. Inhibition of cell wall protein anchoring diminishes virulence potential and results in an impaired capacity to form persistent infections.
In Aim 2 we will proactively characterize the molecular mechanisms of Ramoplanin resistance in Gram-positive bacteria. Lastly, in Aim 3 we will perform structural analyses of Enduracidin and the Enduracidin::Lipid II complex in solution and in membrane environments using solution and solid state NMR approaches. In turn, we hope to apply the knowledge gained to the development of alternative antibiotics with improved activity against infections due to resistant and virulent bacterial phenotypes. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
7R01AI046611-07
Application #
7354938
Study Section
Synthetic and Biological Chemistry B Study Section (SBCB)
Program Officer
Peters, Kent
Project Start
2000-06-01
Project End
2010-03-31
Budget Start
2006-12-20
Budget End
2007-03-31
Support Year
7
Fiscal Year
2006
Total Cost
$268,214
Indirect Cost
Name
Duke University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
044387793
City
Durham
State
NC
Country
United States
Zip Code
27705
Bellucci, Joseph J; Amiram, Miriam; Bhattacharyya, Jayanta et al. (2013) Three-in-one chromatography-free purification, tag removal, and site-specific modification of recombinant fusion proteins using sortase A and elastin-like polypeptides. Angew Chem Int Ed Engl 52:3703-8
Qi, Yizhi; Amiram, Miriam; Gao, Weiping et al. (2013) Sortase-catalyzed initiator attachment enables high yield growth of a stealth polymer from the C terminus of a protein. Macromol Rapid Commun 34:1256-60
Folk, Drew S; Torosian, Justin C; Hwang, Sunhee et al. (2012) Monitoring ýý-secretase activity in living cells with a membrane-anchored FRET probe. Angew Chem Int Ed Engl 51:10795-9
Weinberg, David R; Gagliardi, Christopher J; Hull, Jonathan F et al. (2012) Proton-coupled electron transfer. Chem Rev 112:4016-93
Hoertz, Amanda J; Hamburger, James B; Gooden, David M et al. (2012) Studies on the biosynthesis of the lipodepsipeptide antibiotic Ramoplanin A2. Bioorg Med Chem 20:859-65
Jorgensen, Ine; Bednar, Maria M; Amin, Vishar et al. (2011) The Chlamydia protease CPAF regulates host and bacterial proteins to maintain pathogen vacuole integrity and promote virulence. Cell Host Microbe 10:21-32
Hu, Xiangqian; Hu, Hao; Melvin, Jeffrey A et al. (2011) Autocatalytic intramolecular isopeptide bond formation in gram-positive bacterial pili: a QM/MM simulation. J Am Chem Soc 133:478-85
Melvin, Jeffrey A; Murphy, Christine F; Dubois, Laura G et al. (2011) Staphylococcus aureus sortase A contributes to the Trojan horse mechanism of immune defense evasion with its intrinsic resistance to Cys184 oxidation. Biochemistry 50:7591-9
Cropp, T Ashton; McCafferty, Dewey G (2011) Found in translation: applications of protein and peptide molecular diversity. Curr Opin Chem Biol 15:347-9
Bednar, Maria M; Jorgensen, Ine; Valdivia, Raphael H et al. (2011) Chlamydia protease-like activity factor (CPAF): characterization of proteolysis activity in vitro and development of a nanomolar affinity CPAF zymogen-derived inhibitor. Biochemistry 50:7441-3

Showing the most recent 10 out of 27 publications