Activation of the alternate complement pathway in human serum by several bacterial components was compared. Peptidoglycan from group A streptococcal cell walls was the most active material, on a weight basis, followed by cell walls, protoplast membranes, and whole cells. The group-specific carbohydrate was inactive. Treatment of peptidoglycan with low concentrations of lysozyme or short periods...

In the present study, peptidoglycan from Rickettsia prowazekii, an obligate intracellular bacterium, was purified. The rickettsial peptidoglycan is like that of gram-negative bacteria; that is, it is sodium dodecyl sulfate insoluble, lysozyme sensitive, and composed of glutamic acid, alanine, and diaminopimelic acid in a molar ratio of 1.0:2.3:1.0. The small amount of lysine found in the peptid...

Peptidoglycan is an essential polymer that forms a protective shell around bacterial cell membranes. Peptidoglycan biosynthesis is the target of many clinically used antibiotics, including the beta-lactams, imipenems, cephalosporins, and glycopeptides. Resistance to these and other antibiotics has prompted interest in an atomic-level understanding of the enzymes that make peptidoglycan. Represe...

From a forward genetic screen for phagocytosis mutants in Drosophila melanogaster, we identified a mutation that affects peptidoglycan recognition protein (PGRP) SC1a and impairs the ability to phagocytose the bacteria Staphylococcus aureus, but not Escherichia coli and Bacillus subtilis. Because of the differences in peptidoglycan peptide linkages in these bacteria, our data suggest that PGRP-...

A method was developed to label specifically the glycan chains of the cell wall peptidoglycan of Streptococcus fuecalis ATCC 9790 with [‘“Cl acetate. The formation of peptide cross-links (a) during exponential growth, (b) after valine starvation and wall thickening, and (c) during regrowth after 2 hours of valine starvation, was studied using continuous, pulse and pulse-chase labeling of the pe...

Planctomycetes are intriguing microorganisms that apparently lack peptidoglycan, a structure that controls the shape and integrity of almost all bacterial cells. Therefore, the planctomycetal cell envelope is considered exceptional and their cell plan uniquely compartmentalized. Anaerobic ammonium-oxidizing (anammox) Planctomycetes play a key role in the global nitrogen cycle by releasing fixed...

The qualitative and quantitative chemical composition of the peptidoglycan layer of Listeria monocytogenes cell walls was determined. The peptidoglycan layer was isolated from intact cells after treatment with sodium lauryl sulfate and digestion with Pronase. The isolated peptidoglycan contained carbohydrates which included hexose, rhamnose, and amino sugars. The amino sugar was identified as g...

A particulate enzyme system from Bacillus sfearofhermophilus which catalyzes the synthesis of peptidoglycan from uridine nucleotide precursors has been investigated. The preparation catalyzed extensive cross-linking of the enzymatically synthesized peptidoglycan. In addition in the presence of ATP and ammonia or L-glutamine amidation of the peptidoglycan also occurred. The nature of the amidate...

A constituent of the bacterial cell wall, peptidoglycan, has been suggested to be a significant fraction of marine dissolved organic matter, but little is known about its turnover. We measured hydrolysis and remineralization rates of peptidoglycan in surface waters by using radiolabeled peptidoglycan that was extracted from a Gram-negative bacterium. Polysaccharide (N-acetyl-glucosamine and N-a...

A method was developed to label specifically the glycan chains of the cell wall peptidoglycan of Streptococcus faecalis ATCC 9790 with [14C]acetate. The formation of peptide cross-links (a) during exponential growth, (b) after valine starvation and wall thickening, and (c) during regrowth after 2 hours of valine starvation, was studied using continuous, pulse and pulse-chase labeling of the pep...