Outer membrane proteins of Escherichia coli. V. Evidence that protein 1 and bacteriophage-directed protein 2 are different polypeptides.
AUTOR(ES)
Diedrich, D L
RESUMO
Protein 1 from the outer membrane of Escherichia coli K-12 and protein 2 from a phage PA-2 lysogen of the same strain were isolated by differential sodium dodecyl sulfate extraction and purified by ion-exchange and gel filtration chromatography. Rabbit antisera were prepared against these proteins and showed no cross-reaction between proteins 1 and 2. The proteins have the same N-terminal amino acid but show small yet significant differences in amino acid composition. The proteins were cleaved with cyanogenbromide in solvents containing both formic acid and trifluoroacetic acid. By comparing the cleavage in these solvents, it was established that protein 1 yielded 5 cyanogen bromide peptides, and the sum of the molecular weights of these was equivalent to the molecular weight of the uncleaved protein. Protein 2 yielded 4 cyanogen bromide peptides, none of which was identical to those of protein 1, and the sum of these peptides was also equivalent to the apparent molecular weight of the uncleaved protein. Significant differences were also observed when tryptic peptides from the two proteins were compared. These results indicate that protein 1 and the phage-directed protein 2 are distinct, different, and apparently homogeneous proteins.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=235469Documentos Relacionados
- Outer Membrane Proteins of Escherichia coli VII. Evidence That Bacteriophage-Directed Protein 2 Functions as a Pore
- Dependence of "early" lambda bacteriophage RNA synthesis on bacteriophage-directed protein synthesis.
- Outer membrane proteins of Escherichia coli. VI. Protein alteration in bacteriophage-resistant mutants.
- System for the Investigation of the Bacteriophage-directed Synthesis of Diphtherial Toxin
- Bacteriophage T5 gene A2 protein alters the outer membrane of Escherichia coli.