Peptidoglycans synthesized by a membrane preparation of Micrococcus luteus

Abstract

By incubation of cell-free particulate preparations from Micrococcus luteus with nucleotidic precursors uridine 5'-diphosphate-N-acetylglucosamine and uridine 5'-diphosphate-N-acetylmuramic acid-L-Ala-D-iso-Glu-L-Lys-D-Ala-D-Ala, several types of peptidoglycans were obtained: soluble peptidoglycan, insoluble peptidoglycan bound to the membrane and solubilized by trypsin, and peptidoglycan, which remained insoluble after the action of trypsin. The structure of each type of peptidoglycan was studied by action of lytic enzymes and separation of the fragments on Sephadex. Soluble peptidoglycans consist of a mixture of un-cross-linked polymers of various molecular weights. Trypsinsolubilized peptidoglycans are also a mixture of polymers of various sizes. They contain a preponderance of un-cross-linked material and some bridges with dimer peptides. Insoluble peptidoglycans, after the action of trypsin, contain about 50% of un-cross-linked peptide residues; in the other moiety, peptide units are cross-linked by D-Ala-L-Lys and D-Ala-L-Ala bonds which characterize the natural peptidoglycan. Therefore, the cell-free particulate preparation possesses the whole enzymatic system necessary for synthesis of cross-linked peptidoglycan.

Peptidoglycan biosynthesis in Micrococcus luteus (sodonensis): transglycosidase and phosphodiesterase activities in membrane preparations

“…DISCUSSION The highly active transglycosidase system present in membranes from M. luteus (sodonensis) has made it possible to synthesize peptidoglycan in vitro in large enough amounts to examine its properties. Several similarities were noted between the present study and recent results obtained by Bordet and Perkins 5and Pellon et al (18,19) in their examination of in vitro peptidoglycan biosynthesis by M. luteus (lysodeikticus). They found that newly synthesized peptidoglycan was mainly soluble (52 to 62%) and that a major part of the insoluble peptidoglycan could be solubilized by trypsin digestion, just as insoluble peptidoglycan from M. luteus (sodonensis) can be solubilized by butanol extraction.…”

Formation of the glycan chains in the synthesis of bacterial peptidoglycan

“…In vitro peptidoglycan-synthesizing activity has been elicited with membrane preparations from various organisms (Chatterjee and Park, 1964;Meadow et al, 1964;Anderson et al, 1966;Izaki et al, 1966;Araki et al, 1966;Plapp and Strominger, 1970;Reynolds, 1971;Wickus and Strominger, 1972;Hammes and Neuhaus, 1974;Pellon et al, 1976;van Heijenoort et al, 1978;Kamio et al, 1982;Kraus et al, 1985). Crude cell walls from Gram-positive organisms retain to some extent the functional spatial interrelationships between the membrane and the cell wall and were found to be particularly appropriate for the in vitro study of the polymerization reactions Ward, 1974;Ward and Perkins, 1974;Hammes and Kandler, 1976;Weston et al, 1977;Kalomiris et al, 1982).…”