Engineering outer-membrane proteins in Pseudomonas putida for enhanced heavy-metal bioadsorption

• Published in: Journal of inorganic biochemistry 2000-04, Vol.79 (1), p.219-223
• Main Authors: Valls, Marc, de Lorenzo, Vı́ctor, Gonzàlez-Duarte, Roser, Atrian, Sı́lvia
• Format: Article
• Language: English
• Subjects: Adsorption; Animals; Bacterial Outer Membrane Proteins - genetics; Bacterial Outer Membrane Proteins - metabolism; Bioremediation; Cadmium - metabolism; DNA Transposable Elements; Environmental Pollutants - pharmacokinetics; Heavy metals; IgA protease; Metallothionein; Metallothionein - genetics; Metallothionein - metabolism; Metals, Heavy - pharmacokinetics; Mice; Neisseria - enzymology; Pseudomonas; Pseudomonas putida - genetics; Pseudomonas putida - metabolism; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - metabolism; Serine Endopeptidases - chemistry; Serine Endopeptidases - metabolism
• ISSN: 0162-0134; 1873-3344
• DOI: 10.1016/S0162-0134(99)00170-1

Metallothioneins (MTs) are small, cysteine-rich proteins with a strong metal-binding capacity that are ubiquitous in the animal kingdom. Recombinant expression of MT fused to outer-membrane components of Gram-negative bacteria may provide new methods to treat heavy-metal pollution in industrial sewage. In this work, we have engineered Pseudomonas putida, a per se highly robust microorganism able to grow in highly contaminated habitats in order to further increase its metal-chelating ability. We report the expression of a hybrid protein between mouse MT and the β domain of the IgA protease of Neisseria in the outer membrane of Pseudomonas cells. The metal-binding capacity of such cells was increased three-fold. The autotranslocating capacity of the β domain of the IgA protease of Neisseria, as well as the correct anchoring of the transported protein into the outer membrane, have been demonstrated for the first time in a member of the Pseudomonas genus.