Site of ATPase activity in Myxococcus xanthus: Lipid requirement for enzyme activity

✍ Scribed by Prof. Dr. H. Voelz

• Book ID: 102909298
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 886 KB
• Volume: 18
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.19780180506

✦ Synopsis

Site of ATPase activity in Myxococcus xanthus :

Lipid requirement for enzyme activity

H. VOELZ

Dedicated to Professor Dr. W. SCHWARTZ on his 80th birthday.

(Eingegangen am 11. 4.1977) Treatment of cells with lysophosphatidylcholine, lysozyme, and phospholipase D removed most of their phospholipids and reduced ATPase activity to near zero. Addition of a microdispersion of phospholipids restored enzyme activity to various degrees. Phosphatidylcholine was most effective in reconstitution experiments, less effective were phosphatidylethanolamine and phosphatidylserine. Lipid analyses of cell fractions were possible through separation of cell wall and cell membrane in a sucrose gradient after differentiated treatment of glutaraldehyde fixed cells with lysophosphatidylcholine, lysozyme, and pronase. Phosphatidylcholine was almost exclusively a component of the cell membrane, whereas phosphatidylethanolamine was that of the wall. It is concluded that lipids are necessary for in wiwo function of a Mg-dependent ATPase, and that membrane-associated phosphatidylcholine may serve as a matrix for the enzyme. Lipid extracts made from cells or cell fractions contained plasmologens, not previously reported to occur in Gram-negative, aerobic bacteria.