Peptidoglycan structure in cell walls of parental and filamentous Streptococcus cremoris HP

1974 ◽  
Vol 20 (7) ◽  
pp. 905-913 ◽  
Author(s):  
K. G. Johnson ◽  
I. J. McDonald

Cell walls were prepared from parental and filamentous cells of Streptococcus cremoris HP. In addition to aspartic acid, glutamic acid, alanine, and lysine in a 1:2:3:1 ratio, such preparations contained hot formamide-extractable material composed of glucosamine, glucosa-mine-6-phosphate, glucose, galactose, and rhamnose. Parental and filamentous cell walls contained, respectively, 210 and 225 disaccharide units per milligram. The ratio of muramic acid: peptide subunits was about 1.3 for both preparations.Enzymic and chemical analyses revealed that glycan strands are incompletely substituted, peptide cross-bridging is not mediated by D-alanyl-L-alanyl linkages, peptide subunits are linked together to form large moieties, and no significant differences in peptidoglycan structure exist between parental and filamentous cell walls.Analysis by dinitrophenylation techniques disclosed the presence of significant quantities of glucosamine and muramic acid residues with free amino groups in the peptidoglycans of both cell wall preparations. Conversion of such groups by dinitrophenylation or N-acetylation greatly enhanced the response of cell walls to lysozyme digestion.

1970 ◽  
Vol 25 (11) ◽  
pp. 1294-1301 ◽  
Author(s):  
Dieter Koch ◽  
Karl Heinz Schleifer ◽  
Otto Kandler

Cell walls of Bifidobacterium bifidum var. pennsylvanicus were isolated. The polysaccharide consisted of glucose, galactose and rhamnose. Teichoic acid was not present. The murein (peptidoglycan) contained MurNAc, GlcNH2NAc, ᴅ-Glu, Ala. ʟ-Ser, ᴅ-Asp and L-Orn in a ratio of about 1 : 1 : 1 : 2 : 1 : 1 : 1. In one batch a high amount of ʟ-glutamic acid was found. It was not a constituent of the murein since it remained in the lysozyme insensitive residue.The amino acid sequence of the murein was determined by analyzing the oligopeptides arising during partial acid hydrolysis. It was shown that the peptide subunits attached to the muramic acid are the same as in many other mureins: ʟ-Ala-ᴅ-Glu-ʟ-Orn-D-Ala. The interpeptide bridge consisted of β-ᴅ-aspartyl-ʟ-serine. Since about 35% of aspartic acid and 6% of ornithine are N-terminal in the cell wall, it was assumed that only 60% of the peptide subunits are cross-linked. 4 other strains of B. bifidum proved to contain the same type of murein. While all other strains of other species of Bifidobacterium investigated contained other types of murein, it seems likely that the Orn-Ser-Asp type of the murein is typical of B. bifidum.


1967 ◽  
Vol 105 (2) ◽  
pp. 759-765 ◽  
Author(s):  
K. Clarke ◽  
G. W. Gray ◽  
D. A. Reaveley

1. The insoluble residue and material present in the aqueous layers resulting from treatment of cell walls of Pseudomonas aeruginosa with aqueous phenol were examined. 2. The products (fractions AqI and AqII) isolated from the aqueous layers from the first and second extractions respectively account for approx. 25% and 12% of the cell wall and consist of both lipopolysaccharide and muropeptide. 3. The lipid part of the lipopolysaccharide is qualitatively similar to the corresponding material (lipid A) from other Gram-negative organisms, as is the polysaccharide part. 4. The insoluble residue (fraction R) contains sacculi, which also occur in fraction AqII. On hydrolysis, the sacculi yield glucosamine, muramic acid, alanine, glutamic acid and 2,6-diaminopimelic acid, together with small amounts of lysine, and they are therefore similar to the murein sacculi of other Gram-negative organisms. Fraction R also contains substantial amounts of protein, which differs from that obtained from the phenol layer. 5. The possible association or aggregation of lipopolysaccharide, murein and murein sacculi is discussed.


1969 ◽  
Vol 115 (4) ◽  
pp. 797-805 ◽  
Author(s):  
H R Perkins

β-Hydroxydiaminopimelic acid, together with some diaminopimelic acid, occurs in the cell-wall mucopeptide of certain Actinomycetales. These components were converted into their di-DNP derivatives and separated by chromatography. Hence the relative proportions present in the cell walls of a number of species were measured. The problem of acid-induced inversion of configuration was studied. Of the diaminohydroxypimelic acids isomer B (see Scheme 2; amino groups meso, hydroxy group threo to its neighbouring amino group) always predominated but a small proportion of isomer D (amino groups l, hydroxy group erythro) also occurred. The configuration of the diaminohydroxypimelic acids was determined by periodate oxidation to glutamic γ-semialdehyde, which underwent spontaneous ring-closure. Reduction with sodium borohydride produced optically active proline, the configuration of which was determined by direct measurement of the optical rotation of DNP-proline. Un-cross-linked diaminohydroxypimelic acid in the cell wall was oxidized with periodate in the presence of ammonia. Since the remaining amino group was bound in peptide linkage, ring-closure was prevented and borohydride reduction of the aldehyde–ammonia presumed to be present resulted in the formation of ornithine. The quantity of ornithine was used as a measure of the degree of cross-linking.


1962 ◽  
Vol 115 (1) ◽  
pp. 49-62 ◽  
Author(s):  
Richard M. Krause ◽  
Maclyn McCarty

The trypsinized cell walls of Group C streptococci contain two components, the group-specific carbohydrate and a mucopeptide polymer. Hot formamide extraction of Group C cell walls results in a soluble group-specific carbohydrate fraction and an insoluble mucopeptide residue. This mucopeptide, similar in composition to that of Groups A and A-variant streptococci, contains N-acetylglucosamine, N-acetylmuramic acid, alanine, glutamic acid, lysine, and glycine. It is dissolved by the muralytic enzymes, including lysozyme, which does not attack the whole cell wall. Lysis of the cell wall by phage-associated lysin results in the release of soluble fragments composed of the elements of mucopeptide. Group C carbohydrate extracted with formamide is composed primarily of N-acetylgalactosamine and rhamnose. Serological studies suggest that the specificity of Group C carbohydrate is determined by the N-acetylgalactosamine.


1986 ◽  
Vol 32 (2) ◽  
pp. 176-178 ◽  
Author(s):  
Raili Forsén ◽  
Teuvo Hentunen ◽  
Kaua Valkonen ◽  
Sirpa Kontusaari

Cell walls were isolated from mechanically disrupted cells of the slime-forming, encapsulated Streptococcus cremoris strains T5 and MLS96 by using sucrose gradient centrifugation as the last purification step. This cell wall isolation procedure was developed to obtain cell wall associated protein components. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis revealed several polypeptide bands; the 50 kiloDalton band was major in strain T5 cell walls and the 26 and 30 kiloDalton bands were major in strain MLS96 cell walls. Both strains contained five antigenic polypeptides with molecular radius (Mr) values of 40, 47, 50, 54, and 70 kiloDaltons as analysed by immunoblotting and autoradiography. The polypeptides of strain MLS96 with molecular mass of 40 and 70 kiloDaltons reacted most strongly with homologous anti-whole cell serum. In addition, antigenic polypeptides with molecular mass of 100 and 160 kiloDaltons were also detected in strain T5.


2017 ◽  
Vol 84 (1) ◽  
pp. 32-35 ◽  
Author(s):  
Torben Larsen ◽  
Carlos Fernández

This Technical Research Communication describes new analytical methods for free, unbound glutamic acid and glutamine in protein-free blood plasma and milk and introduces the use of quantitation of free amino groups in the same matrices for descriptive and analytical purposes. The present enzymatic-fluorometric methods are easily performed within one working day, allowing for ‘high throughput’ assays of animal trials. These assays could support and enable further studies in lactation physiology with the objective of improved metabolic health.


1996 ◽  
Vol 313 (3) ◽  
pp. 711-715 ◽  
Author(s):  
Danièle BILLOT-KLEIN ◽  
David SHLAES ◽  
Duncan BRYANT ◽  
David BELL ◽  
Jean van HEIJENOORT ◽  
...  

Resistance to glycopeptide antibiotics in enterococci is due to the synthesis of UDP-MurNAc-tetrapeptide-D-lactate (where Mur is muramic acid) replacing the normal UDP-MurNAc-pentapeptide precursor. The peptidoglycan structures of an inducible VanB-type glycopeptide-resistant Enterococcus faecium, D366, and its constitutively resistant derivative, MT9, were determined. Using HPLC, 17 muropeptides were identified and were present regardless of whether resistance was expressed or not. The structures of 15 muropeptides were determined using MS and amino acid analysis. The cross-bridge between D-alanine and L-lysine consisted of one asparagine. No monomer pentapeptide or tetrapeptide-D-lactate could be identified. These results obtained with D366 (non-induced) and MT9 indicate that, in the absence of vancomycin, the cell wall synthetic machinery of E. faecium can process the lactate-containing precursor as efficiently as the normal pentapeptide. In contrast, the presence of subinhbitory inducing concentrations of vancomycin interfered with the synthesis of oligomers.


1962 ◽  
Vol 116 (2) ◽  
pp. 229-245 ◽  
Author(s):  
Stephen I. Morse

The cell walls of an 80/81 strain of Staphylococcus aureus (NYH-6) contain alanine, glycine, glutamic acid, lysine, muramic acid, glucosamine, and ribitol phosphate. 94 per cent of the phosphorus and 41 per cent of the glucosamine are removed by extraction of the cell walls with hot 5 per cent TCA, but significant amounts of the other constituents are not extracted by this procedure. The residue after hot TCA extraction (mucopeptide) is susceptible to lysozyme whereas the intact cell walls are resistant. Staphylococcus aureus cell walls are agglutinated by S. aureus antisera. Agglutination of the cell walls of one S. aureus strain is inhibited by absorption of antisera with cell walls of other S. aureus strains but not by absorption with S. albus cell walls. The ribitol teichoic acid can be isolated from cold TCA extracts of the cell walls. This compound consists almost entirely of ribitol phosphate and glucosamine. The isolated teichoic acid of strain NYH-6 is readily fixed to tanned sheep erythrocytes and these sensitized cells are agglutinated by S. aureus antisera. Cold TCA extracts of cell walls of other strains of S. aureus inhibit hemagglutination whereas extracts of S. albus walls do not. Studies on the inhibition of both hemagglutination and precipitation indicate that the antigenic determinant of S. aureus NYH-6 teichoic acid is ß-N-acetylglucosamine.


1975 ◽  
Vol 21 (1) ◽  
pp. 79-84 ◽  
Author(s):  
S. Safe ◽  
J. Caldwell

The distribution of chloroform–methanol and alkali-extractable lipids in the cell walls of aerobically grown filamentous cells from Mucor rouxii has been determined. The results have been compared with the corresponding lipid composition of yeast-like cells from M. rouxii, which can be produced in two ways: by growth under anaerobic conditions and by aerobic growth in the presence of 0.22% phenethyl alcohol (PEA). It was observed that in most cases the crude cytoplasmic fraction contained higher levels of several lipids (i.e., squalene, sterols, triterpenes, and fatty acids) than did the corresponding cell walls. The cell walls did, however, contain both "free" (chloroform–methanol extractable) and "bound" (alkali extractable) lipids although the relative amounts were markedly dependent on the cell growth environment. The aerobically grown filamentous cell walls contained higher levels of squalene, sterols, triterpenes, and fatty acids than did aerobically grown yeast-like PEA-induced cell walls and there was also considerable variation in the "free''/"bound" ratios of the various lipid components. The lipid levels in both the cell walls and cytoplasm of the anaerobically grown cells were considerably lower than those of the cells grown under aerobic conditions. In addition, the differences in the growth environment were also reflected in the compositions of the individual lipid fractions from both the cell wall and the cytoplasm fraction.


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