The object of this review is the genus Proteus, which contains bacteria considered now to belong to the opportunistic pathogens. Widely distributed in nature (in soil, water, and sewage), Proteus species play a significant ecological role. When present in the niches of higher macroorganisms, these species are able to evoke pathological events in different regions of the human body. The invaders (Proteus mirabilis, P. vulgaris, and P. penneri) have numerous factors including fimbriae, flagella, outer membrane proteins, lipopolysaccharide, capsule antigen, urease, immunoglobulin A proteases, hemolysins, amino acid deaminases, and, finally, the most characteristic attribute of Proteus, swarming growth, enabling them to colonize and survive in higher organisms. All these features and factors are described and commented on in detail. The questions important for future investigation of these facultatively pathogenic microorganisms are also discussed.

Potential virulence factors of Proteus bacilli.

Molecular structure of lipid A, the endotoxic center of bacterial lipopolysaccharides.

Different applications of the thiobarbituric acid assay were used to determine C4/5-unsubstituted, heptosyl-substituted and total 3-deoxy-d-mannooctulosonic acid (dOclA) in lipopolysaccharides of Salmonella minnesota rough mutants. C4/5-unsubstituted dOclA is determined without prior hydrolysis of the lipopolysaccharides by periodate oxidation near neutral pH at 4°C using the methyl ketoside of dOclA as a standard. C4/5-unsubstituted dOclA, and dOclA which is substituted by other dOclA residues, is quantified after hydrolysis in 0.1 M acetate buffer pH 4.4 at 100°C/1 h. Total dOclA, including heptosyl-substituted dOclA, is measured after hydrolysis in 1 M HCl at 100°C for 1–4 h. For S. minnesota R595, 760–790 nmol/mg lipopolysaccharide are determined independently of the hydrolysis conditions employed. In R7, one half, and in R345, two thirds of the total dOclA content are detected after mild acid hydrolysis. Hydrolysis in 1 M HCl at 100°C for 1 h (R7) and 4 h (R345) are required to liberate the heptosyl-substituted dOclA residues. For the three lipopolysaccharides tested, determination of C4/5-unsubstituted dOclA revealed that about one third of the total dOclA is reactive in this application of the thiobarbituric acid assay. By strong acid hydrolysis, a 3-deoxy-2-ketoaldonic acid is identified in the lipopolysaccharide of Vibrio cholerae. Upon mild and strong acid hydrolysis, a 3-deoxy-2-ketoaldonic acid is identified in the lipopolysaccharide of Vibrio cholerae. Upon mild and strong acid hydrolysis, dOclA undergoes degradation which is recognized by (a) decreased reactivity in the thiobarbituric acid assay (b) changed ultraviolet spectra and (c) development of compounds which are reactive in the thiobarbituric acid assay after reduction with sodium borohydride. The rate of degradation depends on the strength of the acid but is the same for reference and lipopolysaccharide-liberated dOclA under a given hydrolysis condition.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1983.tb07249.x

Differential determination of the 3-Deoxy-D-mannooctulosonic acid residues in lipopolysaccharides of Salmonella minnesota rough mutants.

Culture supernatants from Treponema maltophilum associated with periodontitis in humans and Treponema brennaborense found in a bovine cattle disease accompanied with cachexia caused a dose-dependent TNF-alpha synthesis in human monocytes increasing with culture time. This activity could be reduced significantly by blocking the CD14-part of the LPS receptor using the My 4 mAb and by polymyxin B. In the murine macrophage cell line RAW 264.7, Treponema culture supernatants induced TNF-alpha secretion in a LPS binding protein (LBP)-dependent fashion. To enrich for active compounds, supernatants were extracted with butanol, while whole cells were extracted using a phenol/water method resulting in recovery of material exhibiting a similar activity profile. An LPS-LBP binding competition assay revealed an interaction of the treponeme phenol/water extracts with LBP, while precipitation studies implied an affinity to polymyxin B and endotoxin neutralizing protein. Macrophages obtained from C3H/HeJ mice carrying a Toll-like receptor (TLR)-4 mutation were stimulated with treponeme extracts for NO release to assess the role of TLRs in cell activation. Furthermore, NF-kappaB translocation in TLR-2-negative Chinese hamster ovary (CHO) cells was studied. We found that phenol/water-extracts of the two strains use TLRs differently with T. brennaborense-stimulating cells in a TLR-4-dependent fashion, while T. maltophilum-mediated activation apparently involved TLR-2. These results indicate the presence of a novel class of glycolipids in Treponema initiating inflammatory responses involving LBP, CD14, and TLRs.

Involvement of Lipopolysaccharide Binding Protein, CD14, and Toll-Like Receptors in the Initiation of Innate Immune Responses by Treponema Glycolipids

We have investigated the lipid A of Francisella tularensis subsp. holarctica strain 1547-57, a type B strain, by using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, nanoelectrospray quadrupole ion-trap mass spectrometry, and chemical methods. In accordance with the previously published structures of the lipid A from F. tularensis live vaccine strain (LVS) (ATCC 29684) (E. Vinogradov et al., Eur. J. Biochem. 269:6112-6118, 2002), all of the major lipid A forms from strain 1547-57 were tetraacylated. As in the LVS strain, the major fatty acids detected in the F. tularensis 1547-57 lipid A sample included 3-hydroxyoctadecanoic acid, 3-hydroxyhexadecanoic acid, hexadecanoic acid, and tetradecanoic acid. However, several of the lipid A components present in strain 1547-57 were of higher molecular weight than the previously published structures. A major component with an M(r) of 1,666 was found to contain three C(18:0)(3-OH) fatty acids, one C(16:0) fatty acid, one phosphate group, and one 161-Da moiety. This 161-Da moiety could be removed from the lipid A by treatment with aqueous hydrofluoric acid and was identified as galactosamine following peracetylation and analysis by gas chromatography-mass spectrometry. Detailed investigations of the M(r)-1,666 species by ion-trap mass spectrometry with multiple stages of fragmentation suggested that the galactosamine-1-phosphate was linked to the reducing terminus of the lipid A. Similar to the modification of lipid A with arabinosamine, lipopolysaccharide species from F. tularensis containing a phosphate-linked galactosamine could potentially influence its intracellular survival by conferring resistance to antimicrobial peptides.

Novel modification of lipid A of Francisella tularensis.

The lipopolysaccharide of Acinetobacter calcoaceticus NCTC 10305 (London) was obtained by a modified phenol/chloroform/light petroleum method from the bacterial cells and from the culture medium in yields of 1.6% and 2.2% respectively (based on the bacterial dry weight). On chemical analysis, both preparations proved to be identical. The lipopolysaccharide obtained from the cells was purified by repeated ultracentrifugation, electrodialysis, and precipitation with sodium chloride. It was free of nucleic acids, proteins, and glycans. In the analytical ultracentrifuge, the triethylamine and sodium salt forms of the lipopolysaccharide showed a s20 value of 8.9 S and 51 S, respectively. The lipopolysaccharide consisted of glucosamine, 3-deoxy-D-manno-octulosonic acid, D-glucose, fatty acids, and phosphate in a molar ratio of 2:1:7:6:4. The fatty acids were predominantly lauric acid, 2-hydroxy, and 3-hydroxylauric acid in a molar ratio of 1:1:2. Only 3-hydroxylauric acid was found in amide linkage. On mild acid hydrolysis of the lipopolysaccharide, 65% lipid A were obtained, to which glucosamine was retained quantitatively. It still contained 50% of the original glucose, while one third (15%) of the liberated glucose was in monomeric form.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1982.tb05871.x

Isolation, Purification, and Chemical Analysis of the Lipopolysaccharide Analysis of the Lipopolysaccharide and Lipid A of Acinetobacter calcoaceticus NCTC 10305

The structure of the 4-amino-L-arabinose-lacking lipopolysaccharide of the Proteus mirabilis Rc-type mutant R4, derived from wild-type O28, was elucidated. The lipopolysaccharide core structure has previously been partially characterized. The linkage between heptose and deoxyoctulosonic acid(dOclA) is now reported, as well as the structure of the lipid A moiety of this mutant strain. Besides the tentative identification of an α-linked glucosamine disaccharide in the lipid A backbone accompanying the usual β1 6-linked glucosamine-disaccharide, the only significant structural variation to previous studies was the lack of substitution of the C-4′ phosphate by 4-amino-L-arabinose. In addition, the substitution at C-8 of one dOclA unit by 4-amino-L-arabinose, previously reported for the R45 mutant of P. mirabilis 1959, is lacking in this R mutant. Also in addition to previous findings, the terminal unit of heptose was found to be substituted at C-7 with phosphorylethanolamine (PEtN) and not only with phosphate, although this substitution is not complete as demonstrated by the relevant signals in 31P-NMR. Additional studies with the wild-type strain P. mirabilis O28 revealed the presence of 4-amino-L-arabinose in both the core and the lipid A regions suggesting that the R4 mutant is defective in the biosynthesis of this amino sugar rather than in its transfer. Otherwise the lipid A regions of the mutant and the wild-type strain show no structural differences.



The following formula is proposed for the lipopolysaccharide of 4-amino-L-arabinose-lacking mutant R4/O28 P. mirabilis:

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1988.tb13922.x

Structural studies on the core and lipid A region of a 4-amino-L-arabinose-lacking Rc-type mutant of Proteus mirabilis.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Helmut Brade

Author Tools

Chat about Author

Papers

Isolation, Purification, and Chemical Analysis of the Lipopolysaccharide Analysis of the Lipopolysaccharide and Lipid A of Acinetobacter calcoaceticus NCTC 10305

Structural studies on the core and lipid A region of a 4-amino-L-arabinose-lacking Rc-type mutant of Proteus mirabilis.