title: [Accessible surface and intramolecular mobility of proteins: study by method of tritium planigraphy].
abstract: The method of tritium planigraphy is used for determination of the accessible surface of a globular protein--lysozyme--and the accessibility of particular types of amino acid residues as a function of temperature in the range of 77-193 K. Protein powder with humidity 10 +/- 1% was used. As the temperature is changed from 77 to 160 K for all types of amino acid residues was obtained decreasing of inclusion of tritium label. All types of amino acid residues may be divided on the three groups: I. Accessibility rises under increasing temperature from 160 to 293 K (K, R, H, P, L); II. Accessibility not depends or slightly increases with the growth of temperature (C, V, A, I, Y, F); III. Accessibility strongly increases in the range of the temperature 260-293 K (S, T, G, D + N, E + Q). The reason of "cold denaturation" is perhaps the difference of behaviour of structural water molecules. Under increasing of temperature from 160 to 293 K change of accessibility was explained the growing of intramolecular flexibility of molecule. Under transition from 160 to 77 K for all types of residues is observed sensible change of spatial structure of the protein, which cannot be explained by only participation of dynamical characteristics.
authors.forename: E N
authors.initials: EN
authors.lastname: Bogacheva
authors.forename: N D
authors.initials: ND
authors.lastname: Zhukov
authors.forename: A V
authors.initials: AV
authors.lastname: Shishkov
mesh_terms: D000818:Animals; D002645:Chickens; D009113:Muramidase / Q000737:chemistry*; D011487:Protein Conformation; D011489:Protein Denaturation; D013696:Temperature; D014056:Tomography, X-Ray; D014316:Tritium / Q000737:chemistry
chemical_list: D014316:Tritium; D009113:Muramidase
vernacular_title: Dostupnaia poverkhnost' i vnutrimolekuliarnaia podvizhnost' belkov: issledovanie metodom tritievoĭ planigrafii.