Univerza na Primorskem
Fakulteta za matematiko, naravoslovje in informacijske tehnologije
Več informacij o projektu / More info about the project
Opis / Description
SLO:
Protimikrobna odpornost je ena izmed desetih največjih globalnih javnozdravstvenih težav, saj narašča število bakterijskih okužb, ki jih z razpoložljivimi kemoterapijami ni več mogoče zdraviti. Po podatkih Svetovne zdravstvene organizacije bi lahko, če ne bomo ukrepali, do leta 2050 odporne bakterije povzročile 10 milijonov smrti letno. Zato je nujno odkrivanje in razvoj novih protibakterijskih učinkovin. Pri tem imajo pomembno vlogo manjša podjetja in predvsem akademska sfera, saj so številna velika farmacevtska podjetja prenehala razvijati nove protibakterijske učinkovine.
Okužbe z odpornimi G-bakterijami je posebej težko zdraviti zaradi neprepustnosti njihove zunanje membrane, ki omejuje dostop antibiotikom. Projekt se zato osredotoča na destabilizacijo zunanje membrane in s tem potenciranje delovanja standardnih antibiotikov. V ta namen bosta uporabljena dva vzporedna pristopa, usmerjena v biosintezo bakterijske celične stene.
V prvem pristopu bodo načrtovani in sintetizirani novi inhibitorji D,D-transpeptidaz oziroma penicilin-vezavnih proteinov, ki sodelujejo pri končnih korakih biosinteze peptidoglikana. Na podlagi izkušenj z monocikličnimi beta-laktami bodo razviti novi monobaktami s »super stransko verigo«, substituirani s stranskimi verigami antibiotikov, kot so meropenem in ceftobiprol. Cilj je doseči visoko inhibitorno jakost proti D,D-transpeptidazam, tudi tistim iz odpornih bakterij, ter močno protimikrobno delovanje.
V drugem pristopu bodo razviti specifični zaviralci L,D-transpeptidaz LdtA-C iz Escherichie coli, ki sodelujejo pri pritrditvi lipoproteina Lpp na peptidoglikan in tako zagotavljajo kovalentno povezavo med zunanjo membrano in celično steno. Ker vsebujejo katalitični cistein, bo razvoj inhibitorjev temeljil na izkušnjah z encimi s katalitičnim cisteinom in na odkrivanju zdravil na osnovi fragmentov. Po rešetanjih knjižnic fragmentov bodo z rentgensko kristalografijo ali NMR določeni načini njihove vezave, nato pa bodo z uporabo strukturno-podprtega načrtovanja razvite, sintetizirane in ovrednotene izboljšane spojine.
Novi inhibitorji D,D-transpeptidaz bodo predstavljali spojine vodnice s protibakterijskim delovanjem, medtem ko bodo inhibitorji L,D-transpeptidaz delovali kot potenciatorji, saj bodo povečali prepustnost zunanje membrane G-bakterij in s tem olajšali vstop standardnih antibiotikov v bakterijske celice. Projekt tako predstavlja prvi poskus razvoja in ovrednotenja inhibitorjev LdtA-C kot potenciatorjev.
EN:
Antimicrobial resistance is one of the ten greatest global public health challenges, as the number of bacterial infections that can no longer be treated with available chemotherapies is increasing. According to the World Health Organization, if no action is taken, resistant bacteria could cause 10 million deaths annually by 2050. Therefore, the discovery and development of new antibacterial agents is essential. Small companies and, in particular, the academic sector have an important role to play in this effort, as many large pharmaceutical companies have ceased the development of new antibacterial agents.
Infections with resistant Gram-negative (G−) bacteria are particularly difficult to treat due to the impermeability of their outer membrane, which limits antibiotic access. The project therefore focuses on destabilizing the outer membrane and thereby potentiating the activity of standard antibiotics. To this end, two parallel approaches targeting bacterial cell wall biosynthesis will be employed.
In the first approach, new inhibitors of D,D-transpeptidases, also known as penicillin-binding proteins, which are involved in the final steps of peptidoglycan biosynthesis, will be designed and synthesized. Based on experience with monocyclic beta-lactams, new monobactams with a “super side chain” will be developed, substituted with side chains of antibiotics such as meropenem and ceftobiprole. The aim is to achieve high inhibitory potency against D,D-transpeptidases, including those from resistant bacteria, as well as strong antibacterial activity.
In the second approach, specific inhibitors of the L,D-transpeptidases LdtA-C from Escherichia coli will be developed. These enzymes are involved in the attachment of the lipoprotein Lpp to peptidoglycan, thereby providing a covalent connection between the outer membrane and the cell wall. Since they contain a catalytic cysteine, the development of inhibitors will be based on experience with enzymes containing a catalytic cysteine and on fragment-based drug discovery. Following screening of fragment libraries, their binding modes will be determined by X-ray crystallography or NMR. Subsequently, improved compounds will be developed, synthesized, and evaluated using structure-based design.
The new D,D-transpeptidase inhibitors will represent lead compounds with antibacterial activity, while the L,D-transpeptidase inhibitors will act as potentiators by increasing the permeability of the outer membrane of G− bacteria and thereby facilitating the entry of standard antibiotics into bacterial cells. The project thus represents the first attempt to develop and evaluate LdtA-C inhibitors as potentiators.