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

The cell envelope of Enterobacteriaceae consists of membranes separated by a peptidoglycan layer. have been developed to separate the cytoplasmic from the outer membrane. outer membrane of Escherichia coli contains 60% the envelope protein. Using polyacrylamide, Schnaitman found six protein in the outer membrane fraction, of which one (mol. wt 44 000) accounted for 70% of the total membrane protein.