Improvement of two-dimensional gel electrophoresis proteome maps of the haloarchaeon Haloferax volcanii

Proteins of haloarchaea are remarkably unstable in low-ionic-strength solvents and tend to Received: March 15, 2004 aggregate under standard two-dimensional (2-D) gel electrophoresis conditions, causing strong Revised: May 3, 2004 horizontal streaking. We have developed a new approach to generate 2-D maps of halophilic Accepted: June 30, 2004 proteins which included washing cells with 1.5 m Tris-HCI buffer. In addition, proteins were precipitated with acetone, solubilized with urea and thiourea in the presence of the sulfobetaine detergent 3-[(3-cholamidopropyl)dimethylamino]-1-propanesulfonate (CHAPS), reduced with tributylphosphine (TBP), and separated with microrange strips of immobilized pH gradients (pH 3.9-5.1). This combination enabled the construction of highly reproducible 2-D maps of Haloferax volcanii proteins.