Electrophoretic resolution of the ‘major outer membrane protein’ of <i>Escherichia coli</i> K12 into four bands

Abstract

The cell envelope of Enterobacteriaceae consists of&#13;\ntwo membranes separated by a peptidoglycan layer.&#13;\nMethods have been developed to separate the cytoplasmic&#13;\nmembrane from the outer membrane.&#13;\nThe outer membrane of Escherichia coli contains 60%&#13;\nof the envelope protein. Using polyacrylamide&#13;\ngelelectrophoresis, Schnaitman found six protein&#13;\nbands in the outer membrane fraction, of which one&#13;\nband (mol. wt 44 000) accounted for 70% of the total&#13;\nouter membrane protein.