Isolation and characterization of two outer membrane preparations from Escherichia coli

摘要: Abstract A method was developed for releasing specifically a part of outer membrane during spheroplast formation. highly purified (outer I) obtained from the medium by isopycnic sucrose gradient centrifugation. The remaining II) and cytoplasmic also isolated spheroplasts Two preparations were different in protein composition, enzyme localization, phospholipid lipopolysaccharide content electron micrographs. Although membranes I II almost same various respects, they seemed to be each other under microscope cardiolipin content. It is suggested that II, at least are integrated fashion outer-most layer Escherichia coli cell surface.