In this study, several different depolymerases encoded in the prophage regions of Acinetobacter baumannii genomes have been bioinformatically predicted and recombinantly produced. The identified depolymerases possessed multi-domain structures and were identical or closely homologous to various proteins encoded in other A. baumannii genomes. This means that prophage-derived depolymerases are widespread, and different bacterial genomes can be the source of proteins with polysaccharide-degrading activities. For two depolymerases, the specificity to capsular polysaccharides (CPSs) of A. baumannii belonging to K1 and K92 capsular types (K types) was determined. The data obtained showed that the prophage-derived depolymerases were glycosidases that cleaved the A. baumannii CPSs by the hydrolytic mechanism to yield monomers and oligomers of the K units. The recombinant proteins with established enzymatic activity significantly reduced the mortality of Galleria mellonella larvae infected with A. baumannii of K1 and K92 capsular types. Therefore, these enzymes can be considered as suitable candidates for the development of new antibacterials against corresponding A. baumannii K types.
Acinetobacter baumannii, capsular polysaccharide, glycosidase, capsular type, phage receptor-binding proteins, prophages, structural depolymerase
NCBI PubMed ID: 35563361Publication DOI: 10.3390/ijms23094971Journal NLM ID: 101092791Publisher: Basel, Switzerland: MDPI
Correspondence: A.V. Popova
Institutions: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia, Moscow Institute of Physics and Technology (National Research University), 141700 Dolgoprudny, Russia, Center of Life Sciences, Skolkovo Institute of Science and Technology, 121205 Skolkovo, Russia, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», 123182 Moscow, Russia, State Research Center for Applied Microbiology and Biotechnology, 142279 Obolensk, Russia
Methods: 13C NMR, 1H NMR, NMR-2D, PCR, DNA techniques, mild acid hydrolysis, de-O-acetylation, HPLC, GPC, bioinformatic analysis, phylogenetic analysis, HR-ESI-MS, phage characterization, BLASTp, phage depolymerization
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