Projects / Programmes
Inhibition of Staphylococcus aureus cell wall remodeling
| Code |
Science |
Field |
Subfield |
| 1.05.00 |
Natural sciences and mathematics |
Biochemistry and molecular biology |
|
| Code |
Science |
Field |
| B000 |
Biomedical sciences |
|
| Code |
Science |
Field |
| 1.06 |
Natural Sciences |
Biological sciences |
S.aureus, MRSA, N-acetylglucosaminidase, drug targets, crystal structure, peptidoglycan, biofilm, in silico inhibitor screening
Researchers (11)
Organisations (4)
Abstract
The wide-spread use of antibiotics is resulting in increasing number of antibiotic and multiple antibiotic resistant strains. Among them are the MRSA (methicillin resistant Staphylococcus aureus) and VRSA (vancomycin resistant Staphylococcus aureus). Treatment of such infections is difficult and it urgently calls for new approaches in drug discovery that in turn requires novel insight. Gene knockout and our recent and preliminary studies of S. aureus N-acetyl-glucosaminidases from GH 73 family suggest that these enzymes may indeed play a major role in remodeling of bacterial peptidoglycan cell wall and in formation of biofilm. Our project goal is to validate the drug target potential of N-acetylglucosaminidases from GH 73 family in treatment of S. aureus infections.
During the process we will gain novel insight and understanding of the mechanisms underlying remodeling of the peptidoglycan cell wall of S. aureus and their biofilms. We will study all five members encoded in genome of Staphylococcus aureus Mu50 of the family by complementary approaches of molecular biology, crystal structure analysis, enzyme kinetics, virtual screening based and classical inhibitor design synthesis, biochemical and mass spectroscopy analysis, and by microscopic observation of bacterial planctonic and biofilm cultures (including naturally occurring bacteria and those impaired by knockouts). We believe that research systematically addressing the whole family of N-acetylglucosaminidases together has the potential to deliver fundamental discoveries about their roles in cell wall remodeling and biofilm formation.
Analysis of crystal structure of glucosaminidases from GH 73 family shows substantial differences in the active site cleft. In contrast, the sequence homology of glucosaminidase domains of GH 73 enzymes from S. aureus shows that the residues in the active site are homologues. This suggests that it may be possible to develop an inhibitor that will inhibit only enzymes from S. aureus. Hence, a successful validation of N-acetylglucosaminidases from S. aureus as drug targets opens a perspective to develop drugs that will in a species specific manner treat S. aureus infections and thereby reduce risks of wide spread resistance. In addition, a success in design and synthesis of compounds hampering the whole family of enzymes may deliver new drug prototypes. To conclude, successful outcome will deliver results contributing to novel drug discovery programs and has potential improve human healthcare in life threatening situations of infections with antibiotic resistance strains of S. aureus.
Significance for science
Conducting research in a challenging area of biomedical science related to a well known health problem is a competitive initiative aiming to have a world wide impact.
Insight in molecular mechanisms of the processes and their kinetics at the surface of the cells of S. aureus from the perspective of glucosaminidases by complementary approaches of macromolecular crystallography, organic synthesis, enzyme kinetics, biochemical and mass spectroscopic analysis of degradation products, and observation of physiological phenomena by microscopic imaging has the potential to deliver fundamental discoveries about their roles in cell wall remodeling and biofilm formation. The gained knowledge and successful validation of approach of species specific targeting has the potential to change the view on the treatment of antibiotic resistance S. aureus infections.
Published research in top ranking journals will increase visibility of Slovenian science.
Significance for the country
A subset of drug-resistant bacteria is responsible for about 25,000 human deaths annually. In addition to avoidable death, this also translates into extra healthcare costs and productivity losses of at least 1.5 billion EUR. Approximately 4 million patients are estimated to acquire a healthcare associated infection in the EU every year. Therefore, the availability of effective antibiotic therapy is absolutely crucial for treatment of bacterial infections. Unfortunately, microbial adaptation to selective pressure resulting from antibiotic use inevitably leads to increase of antibiotic resistance. In particular, this is true for S. aureus, which MRSA and VRSA strains are publicly recognizable icons of threats to health. In addition, no new types of antibiotics have been developed in the last 30 years. Main reasons for stalled antibiotic resistance are:
- the "low handing fruits" have been already picked,
- pricing does not reflect societal value, and
- it is more profitable to sell drugs for chronic therapies than antibiotics.
As consequence development of new antibiotics is moving into domain of academic research. Successful completion of this project and possible further developments could deliver a new antibiotic targeting MRSA and VRSA on the market.
The revealed crystal structures, validated targets and the newly discovered compounds may present the resource from which pharmaceutical industry can build novel drug discovery programs. To protect intellectual property, we have already submitted a patent application regarding the crystal structure of autolysin E and its uses. If this research project completes according to expectations, further patents will be submitted which may all enable us to either initiate a new industrial discovery startup or transfer the knowledge to industry.
The last, but not least important, this project is important for the Center of Excellence for integrated approaches in chemistry and biology of proteins (CIPKeBiP), which was established in 2009. It ensures further use of infrastructure of the Centre.
Most important scientific results
Final report
Most important socioeconomically and culturally relevant results
Final report
