Found 2 publications. Displayed publications from 1 to 2
Expand all publications       Show all as text (SweetDB notation)
1. (Article ID: 4581)
 
Morrison MJ, Imperiali B
Biosynthesis of UDP-N,N'-diacetylbacillosamine in Acinetobacter baumannii: Biochemical characterization and correlation to existing pathways
Archives of Biochemistry and Biophysics 536(1) (2013) 72-80
 

The Gram-negative, opportunistic pathogen Acinetobacter baumannii has recently captured headlines due to its ability to circumvent current antibiotic therapies. Herein we show that the multi-drug resistant (MDR) AYE strain of A. baumannii contains a gene locus that encodes three enzymes responsible for the biosynthesis of the highly-modified bacterial nucleotide sugar, UDP-N,N'-diacetylbacillosamine (UDP-diNAcBac). Previously, this UDP-sugar has been implicated in the pgl pathway of Campylobacter jejuni. Here we report the overexpression, purification, and biochemical characterization of the A. baumannii enzymes WeeK, WeeJ, and WeeI that are responsible for the production of UDP-diNAcBac. We also demonstrate the function of the phosphoglycosyltransferase (WeeH), which transfers the diNAcBac moiety to undecaprenyl-phosphate. UDP-diNAcBac biosynthesis in A. baumannii is also directly compared to the homologous pathways in the pathogens C. jejuni and Neisseria gonorrhoeae. This work demonstrates for the first time the ability of A. baumannii to generate the highly-modified, UDP-diNAcBac nucleotide sugar found previously in other bacteria adding to the growing list of pathogens that assemble glycoconjugates including bacillosamine. Additionally, characterization of these pathway enzymes highlights the opportunity for investigating the significance of highly-modified sugars in bacterial pathogenesis.

biosynthesis, Acinetobacter baumannii, bacillosamine, acetyltransferases, aminotransferase, bacterial O-linked glycosylation, UDP-diNAcBac

The publication contains the following compound(s):
 

Expand this publication
2. (Article ID: 6309)
 
Rudenko N, Karatovskaya A, Zamyatina A, Shepelyakovskaya A, Semushina S, Brovko F, Shpirt A, Torgov V, Kolotyrkina N, Zinin A, Kasimova A, Perepelov A, Shneider M, Knirel Y
Immune Response to Conjugates of Fragments of the Type K9 Capsular Polysaccharide of Acinetobacter baumannii with Carrier Proteins
Microbiology Spectrum 10(5) (2022) e0167422
 

The clonal bacterial species Acinetobacter baumannii is an emerging multidrug-resistant pathogen which causes high-lethality infections. Cells of A. baumannii are surrounded by the type-specific capsular polysaccharide (CPS), which provides resistance to the protective mechanisms of the host and is considered a target for immunization. The conjugates of three inert carrier proteins and A. baumannii type K9 CPS fragments, which contained various numbers of oligosaccharide repeats (K-units), were synthesized by periodate oxidation and squaric acid chemistry. The conjugates were applied to immunize mice, and chemical synthesis by squaric acid was shown to significantly improve the immunogenic properties of glycoconjugate. In BALB/c mice, IgG antibodies were predominant among type K9 CPS reactive antibodies, and their total content was several times higher than that of IgM. Immune sera were characterized by their opsonization ability during practically the entire lives of the experimental mice. The sera were cross-reactive, but the highest specificity was observed against the antigen (type K9 CPS) used for immunization. The immunization of BALB/c and ICR-1 mice with a glycoconjugate without adjuvants led to varying degrees of stimulation of IL-10, IL-17A, and TNF-alpha production, but not IL-4 production in the ICR-1 mice. This is in contrast to the BALB/c mice, in which gamma-IFN production was also activated. The protective effectiveness of the glycoconjugates obtained by squaric acid chemistry was demonstrated by experiments that involved challenging immunized and nonimmunized animals with a lethal dose of A. baumannii K9. IMPORTANCE Immunization by glycoconjugates with A. baumannii type K9 CPS fragments induced a high level of antibodies (predominantly IgG) in sera, which reacted specifically with the CPS of A. baumannii type K9, as well as a long immunological memory. The sera of immunized animals efficiently opsonized A. baumannii type K9. Immunization resulted in the balanced production of pro/anti-inflammatory lymphokines and protective antibodies to ensure the survival of the mice infected with A. baumannii. The level of specific antibodies was sufficient to provide protective immunity against the challenge by A. baumannii, making this approach applicable in the development of vaccine preparations.

carbohydrates, carbohydrate, Acinetobacter baumannii, capsular polysaccharide, glycoconjugate, immunochemistry, interleukins, opsonisation assay

The publication contains the following compound(s):
 

Expand this publication

Resort publications by:

New query Export IDs Home Help

Execution: 2 sec