Disease relevance of Muramic acid

• Pneumococcal peptidoglycan amidase (N-acetylmuramoyl-L-alanine amidase, EC 3.5.1.28) and phage CPL1 lysozyme degrade a common substrate (choline-containing pneumococcal cell walls); the former hydrolyzes the bond between muramic acid and alanine, whereas the latter breaks down the linkage between muramic acid and glucosamine [1].
• We report that CCF recognizes lysozyme-predigested Gram-positive bacteria or the peptidoglycan constituent muramyl dipeptide as well as muramic acid [2].
• Muramic acid was found to be present at levels of less than 250-1,700 ng/ml in 12 septic SF samples (10 of which were culture positive for Staphylococcus aureus and 1 each for Escherichia coli and Streptococcus pneumoniae) [3].
• RESULTS: In GC-MS analysis, muramic acid was observed in the ST from 4 of 35 RA patients and from 2 of 14 OA patients, but not in ST from 2 patients with UA and 3 cadavers [4].
• By using the powerful separation technique of capillary gas chromatography combined with the selectivity of mass spectrometric detection, muramic acid was not detectable in purified elementary bodies of Chlamydia psittaci Cal 10 (less than or equal to 0.006%) or C. trachomatis serovar E (less than or equal to 0.02%) [5].

Psychiatry related information on Muramic acid

• We report in the accompanying paper that in the molecular structure of MPs, the 1,6-anhydro muramic acid moiety of MPs is important for enhancement of slow-wave sleep (SWS) in rabbits [6].

High impact information on Muramic acid

• The sensitivity of GC-MS to detect muramic acid was 2 pg/injected amount (227 pg muramic acid/mg ST), and that of the pan-bacterial PCR was 2-20 bacteria colony forming units/reaction [4].
• To identify the pattern recognition domains of CCF, deletion mutants were tested for their ability to reconstitute the prophenoloxidase cascade in E. foetida coelomic fluid depleted of endogenous CCF in the presence of LPS, beta-1,3-glucans, N,N'-diacetylchitobiose, and muramic acid [2].
• Muramic acid from the synovial fluid was studied by gas chromatography-mass spectrometry [7].
• Mass spectrometric quantitation of muramic acid, a bacterial cell wall component, in septic synovial fluids [3].
• We report that in both peptidoglycans, the minimal structure needed to activate the Toll pathway is a muropeptide dimer and that the free reducing end of the N-acetyl muramic acid residues of the muropeptides is essential for activity [8].

Chemical compound and disease context of Muramic acid

• The basic structure of peptidoglycan in B. megaterium spores is similar to that of Bacillus subtilis: 44.2% of muramic acid residues are substituted with delta-lactam, 28.8% with single L-alanine, 25.1% with tetrapeptide and only 1.8% with tripeptide [9].
• This bacterium stained gram-positive, contained a novel fatty-acid profile, had cell wall muramic acid content similar to that of Bacillus subtilis (significantly greater than Escherichia coli), and failed to display a lipopolysaccharide profile in SDS-polyacrylamide gels that would be indicative of a gram-negative cell wall structure [10].
• We studied the association of asthma, hay fever and allergen-specific serum immunoglobulin E with exposure to a farming environment and with levels of endotoxin and muramic acid measured in house dust samples [11].
• Structure of a muramic acid containing capsular polysaccharide from the pathogenic strain of Vibrio vulnificus ATCC 27562 [12].
• The 3-hydroxy fatty acid and muramic acid results demonstrated a much higher proportion of Gram-negative bacteria to Gram-positives in swine dust than in house dust, and ergosterol results demonstrated a much higher proportion of fungi [13].

Biological context of Muramic acid

• Unlike endotoxin, muramic acid was inversely associated with wheezing rather than with atopic sensitization [14].
• The 6-O acetylation of muramic acid enhanced the somnogenic effects of certain monomeric MPs relative to their non-O-acetylated (but otherwise identical) counterparts [15].
• Muramic acid as a measure of microbial biomass in estuarine and marine samples [16].
• A reproducible assay involving acid hydrolysis, preparative thin-layer chromatographic purification, and colorimetric analysis of lactate released from muramic acid by alkaline hydrolysis is described [16].
• Strain IAM 14817(T) (=NCIMB 9991(T)) has the following characteristics: the predominant menaquinones are MK-9 and MK-10, the DNA G+C content is 68 mol%, the diamino acid in the cell wall is 2,4-l-diaminobutyric acid and the muramic acid in the peptidoglycan is of an acetyl type [17].

Anatomical context of Muramic acid

• In summary, there can be an enormous difference in the levels of muramic acid found in different mammalian tissues and body fluids in health and disease [18].
• Failure To detect muramic acid in normal rat tissues but detection in cerebrospinal fluids from patients with Pneumococcal meningitis [18].
• Muramic acid in peripheral blood leukocytes of healthy human subjects [19].
• Therefore, these human spleens were extracted, and after removal of most of the protein, the carbohydrate fraction was investigated for the presence of muramic acid, an amino sugar characteristic for peptidoglycan [20].
• The resulting OMFs of strains 23834 and 470, free of cytoplasmic membrane components, were found to contain 69.6 and 75.0% (wt/wt) protein, 4.8 and 9.2% lipid, 4.6 and 4.7% carbohydrate, and 2.0 and 4.6% muramic acid, respectively [21].

Associations of Muramic acid with other chemical compounds

• Alanine, glutamic acid, diaminopimelic acid, glucosamine, and muramic acid were found in all fractions, in enhanced concentration in PF and BHPF, and with molar ratios typical of bacterial peptidoglycans [22].
• Using three different methods for detection of muramic acid, we found a mean of 3.3 mumol of muramic acid with high-pressure liquid chromatography, 1.9 mumol with a colorimetric method for detection of lactate, and 0.8 mumol with an enzymatic method for detection of D-lactate per spleen (D-lactate is a specific group of the muramic acid molecule) [20].
• The precise levels in mammalian tissues of rhamnose (a constituent of the group-specific polysaccharide) and muramic acid (a constituent of peptidoglycan) at various times after systemic administration of streptococcal cell walls were noted for the first time [23].
• Single-step enantioselective analysis of muramic acid (MA) and diaminopimelic acid (DAP) was achieved by CE via sample enrichment by dynamic pH junction with ortho-phthalaldehyde/N-acetyl-L-cysteine labeling directly in-capillary [24].
• Compared with pure muramic acid, bacterial hydrolysates produced more complex ESI mass spectra, such that the protonated molecular ion at m/z 252 was barely detectable [25].

Gene context of Muramic acid

• HPLC and electrospray ionization tandem mass spectrometry analyses of the cell wall revealed that the muramic acid of peptidoglycan of the wild-type strain was O-acetylated at C6-OH, whereas the muramic acid of the oatA mutant lacked this modification [26].
• This study explored the use of electrospray tandem mass spectrometry (ESI MS/MS) in analysis of underivatized muramic acid in bacterial hydrolysates [25].
• The cell wall materials N-acetyl-D-glucosamine, N-acetyl muramic acid, and protein A were unable to inhibit the coupling of fibronectin to S. aureus [27].
• The absence of muramic acid, adenosine triphosphatase, hexokinase, and nucleic acid as well as electron microscopy indicated that the OM preparations were homogeneous [28].
• CBP, reduced by muramic acid in a post-column reaction, was reoxidized with the amperometric detector, resulting in a highly sensitive and selective detection [29].

Analytical, diagnostic and therapeutic context of Muramic acid

• The total sugar content and the amount of muramic acid, but not bacterial counts and mass, indicated that PS increased fecal bacteria [30].
• It is highest in late stationary phase, with a value of 33.2 or 44% per muramic acid residue, as determined by reverse-phase high-pressure liquid chromatography or gel filtration, respectively [31].
• They are demonstrated in tissue fluids and in synovial fluids by optical microscopy, by their muramic acid, and by transmission electron microscopy [32].

References