Escherichia Coli Outer Membrane Protein A (OmpA) Sequence Differentiation by MALDI-TOF-TOF Analyses of Cyanogen Bromide Digestion Products

摘要

The 38 alleles determined from field isolates, yielded only 20 unique amino acid sequences for the hyper-variable region of OmpA due to synonymous translations. The 20 protein types can mostly be differentiated based on MS data but MS-MS data promises to add more refinement. Additionally, differences observed within a single allele type indicate variation in protein sequence beyond the gene sequenced region. Two areas which warrant further investigation are: Utilizing the additional data within the digest spectrum for more specific bacterial subtyping. Better sample preparation (isolation of membrane proteins) for more consistent spectra and characterization.