title: Purification and properties of a protein factor stimulating peptidoglycan synthesis in toluene- and Licl-treated Bacillus megaterium cells.
abstract: A protein factor, called PG-I, can be solubilized from toluene-treated Bacillus megaterium cells by LiCl extraction. After LiCl extraction, peptidoglycan synthesis by the toluene-treated cells is decreased. Protein PG-I can be added back to the extracted cells to stimulate peptidoglycan synthesis. This factor has now been purified 124-fold. It has a molecular weight of 42,000 as estimated by Sephadex gel filtration in the presence of 0.4 M KCl and 52,000 as determined by sodium dodecyl sulfate disc gel electrophoresis. Periodate-Schiff staining of the polyacrylamide gel indicates that factor PG-I is a glycoprotein. The reconstitution of LiCl-extracted cells requires Mg2+ with an apparent Km of 1.9 X 10(-3) M. The Mg2+ ions can be replaced by Ca2+ and by Mn2+ ions to some extent; Zn2+ and Cu2+ ions had no effect. The available data suggest that factor PG-I is essential for peptidoglycan synthesis and requires at least one thiol group for stimulatory activity.
mesh_terms: D001410:Bacillus megaterium / Q000187:drug effects / Q000378:metabolism*; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000502:physiology*; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent; D006023:Glycoproteins / Q000302:isolation & purification / Q000502:physiology*; D007700:Kinetics; D008094:Lithium / Q000494:pharmacology*; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008970:Molecular Weight; D010457:Peptidoglycan / Q000096:biosynthesis*; D013045:Species Specificity; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D014050:Toluene / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D002413:Cations, Divalent; D006023:Glycoproteins; D010457:Peptidoglycan; D013439:Sulfhydryl Reagents; D014050:Toluene; D008345:Manganese; D008094:Lithium; D008274:Magnesium; D002118:Calcium