title: Phosphorylation and dephosphorylation modulation of an inverse temperature transition.
abstract: Poly[15(IPGVG),(RGYSLG)], where RGYSLG is a protein kinase site, was synthesized. On raising the temperature of a 5 mg/ml solution, this polypeptide undergoes an inverse temperature transition at 18 degrees C in which it folds into a contracted state by optimizing intramolecular hydrophobic interactions. Averaging the data of five experiments, phosphorylation by means of a 3':5' cyclic AMP dependent protein kinase to the extent of one phosphate in 360 residues raises the temperature of the folding transition to 32 degrees C. The shift is completely reversed on dephosphorylation by alkaline phosphatase. Phosphorylation is hereby shown to be the most potent chemical perturbation known for shifting the temperature of an inverse temperature transition, which has been shown to be an efficient mechanism for achieving chemomechanical transduction (mechanochemical coupling).
authors.affiliation: Laboratory of Molecular Biophysics, School of Medicine, University of Alabama, Birmingham 35294-0019.
authors.forename: A
authors.initials: A
authors.lastname: Pattanaik
authors.forename: D C
authors.initials: DC
authors.lastname: Gowda
authors.forename: D W
authors.initials: DW
authors.lastname: Urry
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D000595:Amino Acid Sequence; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D010766:Phosphorylation; D011487:Protein Conformation; D011494:Protein Kinases / Q000378:metabolism*; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D010455:Peptides; D011494:Protein Kinases; D000469:Alkaline Phosphatase