Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The disaccharide-dipeptide N-acetyl-beta-D-glucosaminyl-(1----4)-N-acetylmuramyl-L-alanyl-D-isog lut amine has been obtained by an enzymatic degradation of the peptidoglycan of Actinomadura R39. The peptidoglycan was hydrolyzed successively by the three following enzymes: lysozyme, DD-carboxypeptidase from Streptomyces albus G and gamma-D-glutamyl-meso-diaminopimelate endopeptidase I from Bacillus sphaericus 9602. The by-products of the last reaction were eliminated by successive ion-exchange and gel-permeation chromatographies. Both chemical analysis and mass spectrometry show that the resulting disaccharide-dipeptide is a pure compound.
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PMID:Enzymatic preparation of an immunostimulant, the disaccharide-dipeptide, N-acetyl-beta-D-glucosaminyl-(1----4)-N-acetylmuramyl-L-alanyl-D-is ogl utamine, from a bacterial peptidoglycan. 638 Oct 58

A method was developed for obtaining a homogeneous silkworm hemolymph protein (peptidoglycan recognition protein, PGRP) which has affinity for peptidoglycan and the ability to trigger the prophenoloxidase cascade upon its binding to peptidoglycan. The purified PGRP had a molecular mass of about 19 kDa and is composed of a single polypeptide with an isoelectric point of 6.5. It bound to peptidoglycan in the absence of divalent cation, whereas its binding to beta1,3-glucan and chitin was not detected. N-Acetyl-D-glucosaminyl-(beta1-4)-N-acetylmuramyl-L-alanyl-D-isogluta mine did not inhibit purified PGRP to bind insoluble peptidoglycan, but fragmented soluble peptidoglycan did. PGRP seemed to require peptidoglycan as a possible ligand to keep its glycan portion consisting of at least two or more of the repeating unit. PGRP did not have any detectable lysozyme activity, and its amino acid composition and amino-terminal sequence of 20 amino acid residues were shown to be different from those of silkworm lysozyme. PGRP seems to be a hitherto unknown protein. In the absence of PGRP, the prophenoloxidase cascade in the plasma fraction of hemolymph could not be triggered by peptidoglycan, indicating that some type of activity, capable of activating the cascade, is generated upon their binding. However, the exact nature of this activity is not yet known. The purified PGRP bound to peptidoglycan did not hydrolyze significantly any of the 26 commercially available peptidyl-7-amino-4-methylcoumarins, substrates for various proteases.
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PMID:Purification of a peptidoglycan recognition protein from hemolymph of the silkworm, Bombyx mori. 866 62

The location and nature of the linkage between peptidoglycan and oligoglucans in the cell wall of Mesorhizobium loti HAMBI 1148 have been defined by the analysis of nitrous acid deamination of peptidoglycan glucosaminyl residues. The MurNH(2)-Glc(n) fraction was obtained after converting deaminoacylated and N-deacetylated muramyl residues in the cell wall preparation to lactam forms which were stable during subsequent deamination, followed by reduction and opening of the lactams. GC/MS analysis of this material, subjected to partial hydrolysis and reduction or to methanolysis followed by peracetylation, confirmed the presence of glucosyl residues glycosidically attached to muramic acid. The MALDI-TOF spectroscopic analysis of the deaminated material also revealed the presence of [M-H](-) or [M+Na-2H](-) ions representing fragments containing muramic acid with one to three linked glucose residues. The analysis of fully methylated neutral oligosaccharides released from the peptidoglycan with lysozyme followed by borohydride reduction showed the presence of di- and trisaccharides lacking the reducing end.
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PMID:Localization of the attachment site of oligoglucans to Mesorhizobium loti HAMBI 1148 murein. 1929 34