title: Computational design of a water-soluble analog of phospholamban.
abstract: Membrane proteins and water-soluble proteins share a similar core. This similarity suggests that it should be possible to water-solubilize membrane proteins by mutating only their lipid-exposed residues. We have developed computational tools to design water-soluble variants of helical membrane proteins, using the pentameric phospholamban (PLB) as our test case. To water-solublize PLB, the membrane-exposed positions were changed to polar or charged amino acids, while the putative core was left unaltered. We generated water-soluble phospholamban (WSPLB), and compared its properties to its predecessor PLB. In aqueous solution, WSPLB mimics all of the reported properties of PLB including oligomerization state, helical structure, and stabilization upon phosphorylation. We also characterized the truncated mutant WSPLB (21-52) comprising only the former transmembrane segment of PLB. This peptide shows a decreased specificity for forming a pentameric oligomerization state.
authors.affiliation: Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia 19104-6059, USA.
authors.forename: Avram M
authors.initials: AM
authors.lastname: Slovic
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Summa
authors.forename: James D
authors.initials: JD
authors.lastname: Lear
authors.forename: William F
authors.initials: WF
authors.lastname: DeGrado
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D002135:Calcium-Binding Proteins / Q000737:chemistry*; D002942:Circular Dichroism; D017076:Computer-Aided Design; D015195:Drug Design; D008565:Membrane Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry; D010766:Phosphorylation; D011489:Protein Denaturation; D015202:Protein Engineering; D020836:Protein Structure, Quaternary; D012995:Solubility; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*; D000099211:Phospholamban
chemical_list: D002135:Calcium-Binding Proteins; D008565:Membrane Proteins; D010446:Peptide Fragments; D014867:Water; D000099211:Phospholamban