ABSTRACT
Staphylococcus aureus is one of the most dangerous pathogens commonly associated with high levels of morbidity and mortality. Sortase A is considered as a promising molecular target for the development of antistaphylococcal agents. Using hybrid virtual screening approach and FRET analysis, we have identified five compounds able to decrease the activity of sortase A by more than 50% at the concentration of 200 µM. The most promising compound was 2-(2-amino-3-chloro-benzoylamino)-benzoic acid which was able to inhibit S. aureus sortase A at the IC50 value of 59.7 µM. This compound was selective toward sortase A compared to other four cysteine proteases - cathepsin L, cathepsin B, rhodesain, and the SARS-CoV2 main protease. Microscale thermophoresis experiments confirmed that this compound bound sortase A with KD value of 189 µM. Antibacterial and antibiofilm assays also confirmed high specificity of the hit compound against two standard and three wild-type, S. aureus hospital infection isolates. The effect of the compound on biofilms produced by two S. aureus ATCC strains was also observed suggesting that the compound reduced biofilm formation by changing the biofilm structure and thickness.
Subject(s)
COVID-19 , Staphylococcal Infections , Aminoacyltransferases , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Biofilms , Cysteine Endopeptidases , Humans , Microbial Sensitivity Tests , RNA, Viral/pharmacology , SARS-CoV-2 , Staphylococcus aureusABSTRACT
Human protein kinase CK2 is one of the most intriguing enzymes, which functional role still remains unclear despite of decades of studying. At present there is abundant evidence pointing to the fact that inhibitors of CK2 could be used as pharmaceutical agents to treat cancer, viral infections and inflammatory diseases. Here we report novel synthetic flavone inhibitors, 4'-hydroxyflavones, possessing high activity towards CK2. These compounds were identified with receptor-based virtual screening and then chemically optimized on the base of rationale derived from biochemical screening and molecular modeling. It has been demonstrated that synthetic flavone derivatives are much more potent CK2 inhibitors than the natural ones, and we believe that their further examination will be helpful for studying biological role of CK2 as well as for development of new kinase-oriented drugs.
Subject(s)
Casein Kinase II/antagonists & inhibitors , Flavones/chemistry , Protein Kinase Inhibitors/chemistry , Binding Sites , Casein Kinase II/genetics , Casein Kinase II/metabolism , Drug Design , Drug Evaluation, Preclinical , Flavones/chemical synthesis , Flavones/metabolism , Humans , Kinetics , Molecular Docking Simulation , Protein Binding , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/metabolism , Protein Structure, Tertiary , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Structure-Activity RelationshipABSTRACT
Serine/threonine protein kinase CK2 controls vast variety of fundamental processes in cell life; however, despite long period of study, its functional role is not completely determined. CK2 has a significant pathogenic potential and its activity is strictly associated with the development of various kinds of disorders. There are a growing number of facts that inhibitors of CK2 could be used as pharmaceutical agents for the cancer treatment, viral infections, and inflammatory diseases. In this article, we report structural and biological data on the novel synthetic flavonol derivatives, 3-hydroxy-4'-carboxyflavones, possessing a high inhibitory activity toward CK2. With the aid of combinatorial organic synthesis, molecular modeling techniques and biochemical in vitro tests, we studied the structure-activity relationships of flavonol derivatives and developed binding model describing their key intermolecular interactions with the CK2 ATP-binding site. Obtained data show that the synthetic 3-hydroxy-4'-carboxyflavones possess the highest activity among flavonol inhibitors of CK2 known till date.
Subject(s)
Casein Kinase II/antagonists & inhibitors , Drug Discovery , Flavonols/pharmacology , Protein Kinase Inhibitors/pharmacology , Casein Kinase II/metabolism , Catalytic Domain , Flavonols/chemistry , Humans , Hydrogen Bonding/drug effects , Kinetics , Molecular Dynamics Simulation , Protein Kinase Inhibitors/chemistry , Structure-Activity Relationship , Substrate Specificity/drug effects , ThermodynamicsABSTRACT
Due to the emerging role of protein kinase CK2 as a molecule that participates not only in the development of some cancers but also in viral infections and inflammatory failures, small organic inhibitors of CK2, besides application in scientific research, may have therapeutic significance. In this paper, we present a new class of CK2 inhibitors-3-carboxy-4(1H)-quinolones. This class of inhibitors has been selected via receptor-based virtual screening of the Otava compound library. It was revealed that the most active compounds, 5,6,8-trichloro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (7) (IC(50) = 0.3 microM) and 4-oxo-1,4-dihydrobenzo[h]quinoline-3-carboxylic acid (9) (IC(50) = 1 microM), are ATP competitive (K(i) values are 0.06 and 0.28 microM, respectively). Evaluation of the inhibitors on seven protein kinases shows considerable selectivity toward CK2. According to theoretical calculations and experimental data, a structural model describing the key features of 3-carboxy-4(1H)-quinolones responsible for tight binding to CK2 active site has been developed.
