An outer membrane protein characteristic of mucoid strains of Pseudomonas aeruginosa.

SDS-polyacrylamide gel electrophoresis of outer membrane (OM) proteins of different mucoid strains of P. aeruginosa revealed a protein of about 54 kDa that was absent in nonmucoid strains. This 54 kDa protein was expressed under iron-restricted and iron sufficient growth conditions. Electrophoretic mobility of the 54 kDa protein was modified by the solubilization temperature as well as by the addition of lipopolysaccharide and alginate prior to electrophoresis. Treatment of OMs with octylglucoside/KCl or SDS completely extracted the 54 kDa protein at low temperatures. The possible role of this protein in biosynthesis and/or excretion of bacterial alginate is discussed.