FIG. 4.

Analysis of the electrophoretic mobility of GelE proline substitution mutant proteins. Gelatinases purified from culture supernatants of strain FA2-2 expressing the wild-type protein (GelE wt) and the E303P, D304P, I305P, and Q306P mutant proteins were run on a 12% SDS-PAGE gel and stained with Coomassie blue. The broad range protein marker (New England Biolabs) (lanes MW) was included in the analysis. The molecular weights of the five proteins were determined by matrix-assisted laser desorption ionization—time of flight mass spectrometry. MW, molecular weight.