title: The physical state of water in living cells and model systems. XII. The influence of the conformation of a protein on the solubility of Na+ (sulfate), sucrose, glycine and urea in the water in which the protein is also dissolved.
abstract: In this report, we describe the result of an extensive investigation of the effects of the conformations of proteins on the solvency of the bulk-phase water in which the proteins are dissolved. The concentrations of the proteins used were usually between 20 to 40%; the temperature was 25 degrees +/- 1 degree C. To probe the solvency of the water, the apparent equilibrium distribution coefficients (or p-values) of 4 solutes were studied: Na+ (sulfate), glycine, sucrose, and urea. From 8 to 14 isolated proteins in three types of conformations were investigated: native; denatured by agents that unravel the secondary structure (e.g., alpha-helix, beta-pleated sheet) of the protein (i.e., 9 M urea, 3 M guanidine HCl); denatured by agents that only disrupt the tertiary structure but leave the secondary structure intact or even strengthened (i.e., 0.1 M sodium dodecylsulfate or SDS, 2 M n-propanol). The results are as follows: (1) as a rule, native proteins have no or weak effect on the solvency of the water for all 4 probes; (2) exposure to 0.1 M SDS and to 2 M n-propanol, as a rule, does not significantly decrease the p-value of all 4 probes; (3) exposure to 9 M urea and to 3 M guanidine HCl consistently lowers the p-values of sucrose, glycine and Na+ (sulfate) and equally consistently produces no effect on the p-value of urea. Sucrose, glycine, and Na+ are found in low concentrations in cell water while urea is not. These experiments were designed and carried out primarily to test two subsidiary theories of the AI hypotheses: the polarized multilayer (PM) theory of cell water; and the theory of size-dependent solute exclusion.(ABSTRACT TRUNCATED AT 400 WORDS)
authors.affiliation: Damadian Foundation for Basic and Cancer Research, FONAR Corporation, Melville, New York 11747.
authors.forename: G N
authors.initials: GN
authors.lastname: Ling
authors.forename: M M
authors.initials: MM
authors.lastname: Ochsenfeld
mesh_terms: D000433:1-Propanol / Q000494:pharmacology; D000818:Animals; D001834:Body Water / Q000502:physiology*; D005998:Glycine / Q000494:pharmacology; D006146:Guanidines / Q000494:pharmacology; D007700:Kinetics; D011487:Protein Conformation; D011489:Protein Denaturation; D011506:Proteins / Q000502:physiology; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D012995:Solubility; D013395:Sucrose / Q000494:pharmacology; D013431:Sulfates / Q000494:pharmacology; D014508:Urea / Q000494:pharmacology
chemical_list: D006146:Guanidines; D011506:Proteins; D013431:Sulfates; C012036:sodium sulfate; D012967:Sodium Dodecyl Sulfate; D013395:Sucrose; D014508:Urea; D000433:1-Propanol; D005998:Glycine