scholarly journals Novel Serine/Threonine-O-glycosylation with N-Acetylneuraminic acid and 3-Deoxy-D-manno-octulosonic acid by Maf glycosyltransferases

2020 ◽  
Author(s):  
Aasawari Khairnar ◽  
Sonali Sunsunwal ◽  
Ponnusamy Babu ◽  
T.N.C. Ramya

AbstractSome bacterial flagellins are O-glycosylated on surface-exposed Serine/Threonine residues with nonulosonic acids such as pseudaminic acid, legionaminic acid, and their derivatives by flagellin nonulosonic acid glycosyltransferases, also called Motility associated factors (Maf). We report here two new glycosidic linkages previously unknown in any organism, Serine/Threonine-O-linked N-Acetylneuraminic acid (Ser/Thr-O-Neu5Ac) and Serine/Threonine-O-linked 3-Deoxy-D-manno-octulosonic acid (Ser/Thr-O-KDO), both catalysed by Geobacillus kaustophilus Maf (putative flagellin sialyltransferase) and Clostridium botulinum Maf (putative flagellin legionaminic acid transferase). We identified these novel glycosidic linkages in recombinant G. kaustophilus and C. botulinum flagellins that were co-expressed with their cognate recombinant Maf protein in Escherichia coli strains producing the appropriate nucleotide sugar glycosyl donor. The glycosylation of G. kaustophilus flagellin with KDO, and that of C. botulinum flagellin with Neu5Ac and KDO indicates that Maf glycosyltransferases display donor substrate promiscuity. Maf glycosyltransferases have the potential to radically expand the scope of neoglycopeptide synthesis and posttranslational protein engineering.Significance StatementGlycosylation, the modification of proteins with sugars, is one of the most common post-translational modifications observed in proteins. While glycosylation is versatile, the most common forms of glycosylation are N-glycosylation, where the N atom of Asparagine is modified with a glycan, and O-glycosylation where the O atom of serine or threonine residues is modified with a glycan. Here, we report a novel type of O-glycosylation in the bacterial flagellin proteins of two Gram-positive bacteria, Geobacillus kaustophilus and Clostridium botulinum. We demonstrate for the first time that the enzyme flagellin Maf glycosyltransferase is capable of transferring the monosaccharides, N-acetylneuraminic acid and 3-Deoxy-D-manno-octulosonic acid, on to serine and threonine residues of these proteins.

Author(s):  
Aasawari Khairnar ◽  
Sonali Sunsunwal ◽  
Ponnusamy Babu ◽  
T N C Ramya

Abstract Some bacterial flagellins are O-glycosylated on surface-exposed serine/threonine residues with nonulosonic acids such as pseudaminic acid, legionaminic acid and their derivatives by flagellin nonulosonic acid glycosyltransferases, also called motility-associated factors (Maf). We report here two new glycosidic linkages previously unknown in any organism, serine/threonine-O-linked N-acetylneuraminic acid (Ser/Thr-O-Neu5Ac) and serine/threonine-O-linked 3-deoxy-D-manno-octulosonic acid or keto-deoxyoctulosonate (Ser/Thr-O-KDO), both catalyzed by Geobacillus kaustophilus Maf and Clostridium botulinum Maf. We identified these novel glycosidic linkages in recombinant G. kaustophilus and C. botulinum flagellins that were coexpressed with their cognate recombinant Maf protein in Escherichia coli strains producing the appropriate nucleotide sugar glycosyl donor. Our finding that both G. kaustophilus Maf (putative flagellin sialyltransferase) and C. botulinum Maf (putative flagellin legionaminic acid transferase) catalyzed Neu5Ac and KDO transfer on to flagellin indicates that Maf glycosyltransferases display donor substrate promiscuity. Maf glycosyltransferases have the potential to radically expand the scope of neoglycopeptide synthesis and posttranslational protein engineering.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hüseyin Can ◽  
Sedef Erkunt Alak ◽  
Ahmet Efe Köseoğlu ◽  
Umut Şahar ◽  
Berna Bostanbaş ◽  
...  

Abstract Background Cytidine monophospho-n-acetylneuraminic acid hydroxylase (CMAH) gene associated with blood groups in cats encodes CMAH enzyme that converts Neu5Ac to Neu5Gc. Although variations in CMAH gene of pedigree cats have been revealed, the presence/lack of them in non-pedigree stray cats is unknown. Therefore, the present study aimed to investigate the variations in CMAH gene and the quantity of Neu5Ac and Neu5Gc on erythrocytes of non-pedigree stray cats (n:12) living in İzmir, Turkey. Also, the frequency of blood types was determined in 76 stray cats including 12 cats that were used for CMAH and Neu5A/Neu5Gc analysis. Results In total, 14 SNPs were detected in 5’UTR as well as in exon 2, 4, 9, 10, 11 and 12 of CMAH gene. Among these SNPs, -495 C > T in 5’UTR was detected for the first time as heterozygous in type A and AB cats, and homozygous and heterozygous in type B cats. The remaining 13 that have been detected in previous studies were also found as homozygous or heterozygous. Both Neu5Gc and Neu5Ac were detected in type A and AB cats. In type B cats, only Neu5Ac was detected. Among two type AB cats, the level of Neu5Ac was found higher in cat carrying heterozygous form (T/C) of 1392T > C. The prevalence of type B cats (67.1 %) was higher than others. Conclusions The presence of a new SNP as well as previous SNPs indicates that more variations can be found in stray cats with a more comprehensive study in the future. Also, the high prevalence of type B cats demonstrates the possible risk of neonatal isoerythrolysis among stray cats living in İzmir, Turkey.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xinjin Chen ◽  
Bolin Fan ◽  
Chenlong Fan ◽  
Zhongliang Wang ◽  
Eakapol Wangkahart ◽  
...  

Abstract Backgroud Streptococcus agalactiae is a common colonizer of the rectovaginal tract and lead to infectious diseases of neonatal and non-pregnant adults, which also causes infectious disease in fish and a zoonotic risk as well. Lysine crotonylation (Kcr) is a kind of histone post-translational modifications discovered in 2011. In yeast and mammals, Kcr function as potential enhancers and promote gene expression. However, lysine crotonylation in S. agalactiae has not been studied yet. Methods In this study, the crotonylation profiling of fish pathogen, S. agalactiae was investigated by combining affinity enrichment with LC MS/MS. The Kcr modification of several selected proteins were further validated by Western blotting. Results In the present study, we conducted the proteome-wide profiling of Kcr in S. agalactiae and identified 241 Kcr sites from 675 screened proteins for the first time. Bioinformatics analysis showed that 164 sequences were matched to a total of six definitively conserved motifs, and many of them were significantly enriched in metabolic processes, cellular process, and single-organism processes. Moreover, four crotonylation modified proteins were predicted as virulence factors or to being part of the quorum sensing system PTMs on bacteria. The data are available via ProteomeXchange with identifier PXD026445. Conclusions These data provide a promising starting point for further functional research of crotonylation in bacterial virulence in S. agalactiae.


2018 ◽  
pp. 53-60
Author(s):  
Владимир (Vladimir) Александрович (Аleksandrovich) Куркин (Kurkin) ◽  
Татьяна (Tat'yana) Константиновна (Konstantinovna) Рязанова (Ryazanova) ◽  
Александр (Аleksandr) Викторович (Viktorovich) Жестков (Zhestkov) ◽  
Артем (Аrtem) Викторович (Viktorovich) Лямин (Lyamin) ◽  
Елена (Elena) Владимировна (Vladimirovna) Авдеева (Avdeeva) ◽  
...  

The aim of this paper is the isolation of individual compounds, which are caused the antibacterial activity of the leaves of the bearberry [Arctostaphylos uva-ursi (L.) Spreng.]. The leaves of Arctostaphylos uva-ursi, collected in Perm region, there were extracted with 70% ethanol, the obtained water-alcoholic infusion there was evaporated in vacuum.By means of the chromatographic methods with the using of silica gel 40/100 and eluent systems (chloroform and ethanol in several ratio) from the evaporated water-alcoholic extract of the leaves of Arctostaphylos uva-ursi, a substance with antibacterial activity, ethyl ester of p-digallic acid, which is a new natural compound, was isolated along with arbutin ((1-О-b-D-glucopyranoside of hydroquinone) from the leaves of this plant. The chemical structures of the ethyl ester of p-digallic acid and arbutin were established with the using of data of 1H-NMR-spectroscopy, UV-spectroscopy and mass-spectrometry..The antibacterial activity of ethyl ester of p-digallic acid against test cultures of gram-positive bacteria Bacillus cereus and Staphylococcus aureus, gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa for the first time was determined. By antibacterial activity, arbutin was inferior not only to ethyl ester of p-digallic acid, but also to decoction from the leaves of the bearberry. Consequently, the ethyl ester of p-digallic acid is one in main component, which is take the contribution in the antibacterial activity of the decoction and other preparations of the leaves of Arctostaphylos uva-ursi.


2006 ◽  
Vol 397 (1) ◽  
pp. 195-201 ◽  
Author(s):  
Jijun Hao ◽  
Willie F. Vann ◽  
Stephan Hinderlich ◽  
Munirathinam Sundaramoorthy

The most commonly occurring sialic acid Neu5Ac (N-acetylneuraminic acid) and its deaminated form, KDN (2-keto-3-deoxy-D-glycero-D-galacto-nonulosonic acid), participate in many biological functions. The human Neu5Ac-9-P (Neu5Ac 9-phosphate) synthase has the unique ability to catalyse the synthesis of not only Neu5Ac-9-P but also KDN-9-P (KDN 9-phosphate). Both reactions are catalysed by the mechanism of aldol condensation of PEP (phosphoenolpyruvate) with sugar substrates, ManNAc-6-P (N-acetylmannosamine 6-phosphate) or Man-6-P (mannose 6-phosphate). Mouse and putative rat Neu5Ac-9-P synthases, however, do not show KDN-9-P synthase activity, despite sharing high sequence identity (>95%) with the human enzyme. Here, we demonstrate that a single mutation, M42T, in human Neu5Ac-9-P synthase can abolish the KDN-9-P synthase activity completely without compromising the Neu5Ac-9-P synthase activity. Saturation mutagenesis of Met42 of the human Neu5Ac-9-P synthase showed that the substitution with all amino acids except leucine retains only the Neu5Ac-9-P synthase activity at levels comparable with the wild-type enzyme. The M42L mutant, like the wild-type enzyme, showed the additional KDN-9-P synthase activity. In the homology model of human Neu5Ac-9-P synthase, Met42 is located 22 Å (1 Å=0.1 nm) away from the substrate-binding site and the impact of this distant residue on the enzyme functions is discussed.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Christiane Schineider Machado ◽  
João Benhur Mokochinski ◽  
Tatiana Onofre de Lira ◽  
Fátima de Cassia Evangelista de Oliveira ◽  
Magda Vieira Cardoso ◽  
...  

The chemical composition and biological activity of a sample of yellow propolis from Mato Grosso do Sul, Brazil (EEP-Y MS), were investigated for the first time and compared with green, brown, and red types of Brazilian propolis and with a sample of yellow propolis from Cuba. Overall, EEP-Y MS had different qualitative chemical profiles, as well as different cytotoxic and antimicrobial activities when compared to the other types of propolis assessed in this study and it is a different chemotype of Brazilian propolis. Absence of phenolic compounds and the presence of mixtures of aliphatic compounds in yellow propolis were determined by analysing1H-NMR spectra and fifteen terpenes were identified by GC-MS. EEP-Y MS showed cytotoxic activity against human tumour strain OVCAR-8 but was not active against Gram-negative or Gram-positive bacteria. Our results confirm the difficulty of establishing a uniform quality standard for propolis from diverse geographical origins. The most appropriate pharmacological applications of yellow types of propolis must be further investigated.


2009 ◽  
Vol 55 (5) ◽  
pp. 627-632 ◽  
Author(s):  
Thomas Candela ◽  
Marie Moya ◽  
Michel Haustant ◽  
Agnès Fouet

Poly-γ-glutamate has been described in many Gram-positive organisms. When anchored to the surface, it is a capsule and as such a virulence factor. Based on sequence similarities, few Gram-negative organisms have been suggested to synthesize poly-γ-glutamate. For the first time, a Gram-negative bacterium, Fusobacterium nucleatum , is shown to produce and secrete poly-γ-glutamate. Putative poly-γ-glutamate-synthesizing genes from Gram-negative organisms have been compared with their Gram-positive homologs by in silico analysis, i.e., gene sequence and phylogenetic analysis. Clusters of three instead of four genes were highlighted by our screen. The products of the first two genes display similarity with their Gram-positive equivalents, yet the sequences from the Gram-negative organisms can be distinguished from those of the Gram-positives. Interestingly, the sequence of the predicted product of the third gene is conserved among Gram-negative bacteria but displays no similarity to that of either the third or fourth gene of the Gram-positive operons. It is suggested that, like for Gram-positive bacteria, poly-γ-glutamate has a role in virulence for pathogens and one in survival for other Gram-negative bacteria.


1972 ◽  
Vol 50 (7) ◽  
pp. 738-740 ◽  
Author(s):  
Sailen Mookerjea ◽  
M. Alex Michaels ◽  
Roger L. Hudgin ◽  
Mario A. Moscarello ◽  
Annie Chow ◽  
...  

Enzymes which transfer N-acetylneuraminic acid and N-acetylglucosamine from their respective nucleotide-sugars to exogenously added glycoprotein acceptors are present in human sera. The levels of these enzymes have been determined in various pathological sera. Sialyltransferase and N-acetylglucosaminyltransferase levels were increased in a group of patients with various liver diseases. N-Acetylglucosaminyltransferase levels were also increased in a group of patients with a variety of infections. The data support the conclusion that these serum enzymes are derived at least in part from the liver.


Biology ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 29 ◽  
Author(s):  
Thomas M. Hering ◽  
Justin A. Beller ◽  
Christopher M. Calulot ◽  
Diane M. Snow

The role of proteoglycans in the central nervous system (CNS) is a rapidly evolving field and has major implications in the field of CNS injury. Chondroitin sulfate proteoglycans (CSPGs) increase in abundance following damage to the spinal cord and inhibit neurite outgrowth. Major advances in understanding the interaction between outgrowing neurites and CSPGs has created a need for more robust and quantitative analyses to further our understanding of this interaction. We report the use of a high-throughput assay to determine the effect of various post-translational modifications of aggrecan upon neurite outgrowth from NS-1 cells (a PC12 cell line derivative). Aggrecan contains chondroitin sulfate, keratan sulfate, and N-linked oligosaccharides (N-glycans), each susceptible to removal through different enzymatic digestions. Using a sequential digestion approach, we found that chondroitin sulfate and N-glycans, but not keratan sulfate, contribute to inhibition of neurite outgrowth by substrate-bound aggrecan. For the first time, we have shown that N-linked oligosaccharides on aggrecan contribute to its inhibition of neuritogenesis.


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