[Acute angle x-ray scattering by phospholipid membranes after treatment with valinomycin]. / Rasseianie pod malymi uglami rentgenovskikh luchei fosfolipidnymi membranami pri vvedenii valinomitsina.

It has been found by means of small-angle X-ray analysis of oriented bilayers of synthetic dimyristoyl phosphatidyl choline that the introduction of valinomycin modifies their structure and these modifications depend on the phase state of lipid.

[Quaternary structure of histidine decarboxylase according to small-angle x-ray diffraction and electron microscopic findings]. / Chetvertichnaia struktura gistidindekarboksilazy po dannym rentgenovskogo malouglovogo rasseianiia i élektronnoi mikroskopii.

The data on small angle X-ray scattering with histidine decarboxilase (HDC) from Micrococcus sp. n. were analysed and a line of succesively improving approximations of the molecule shape was found: by oblate ellipsoid a:b:c = 1:10.63, by continuous cylinder and hollow cylinder with H = 50 A, 2R = 76 A, 2r = 8A. Biochemical data and electron micrographs of HDC obtained made possible to distinguish subunits and thus to increase resolution of the model. The model of the enzyme molecule consisting of three subunits is suggested, whose X-ray small angle scattering curve well agrees with the experimental one up to value S = 0.21 A-1.

[X-ray diffraction in the intact isolated frog ocular lens]. / Difraktsiia rentgenovskikh luchei na tselom izolirovannom khrustalike glaza liagushki.

X-ray diffraction method has been applied for investigating ocular lens native tissue of the frog. X-ray diffraction patterns of intact lenses, their nuclei and cortices are similar and contain a set of concentric diffuse diffraction maxima. The most intensive of these maxima corresponding to the Bragg-spacings of 14.6, 9.1 and 4.6 A are presumably associated with intramolecular structure of lens proteins--crystallins. Intensive small-angle X-ray scattering and diffraction patterns isotropy indicates unavailability of crystallin molecule ordering or orientation in the lens. The shift of 14.6 A maximum up to 12.8 A being the result of nuclei drying shows the necessity of aqueous surrounding for these protein native structure maintenance.

[Comparative study of bovine ocular lens proteins in native tissue and an extract using the x-ray diffraction method]. / Sravnitel'noe issledovanie belkov khrustalika glaza byka v nativnoi tkani i v ékstrakte metodom difraktsii rentgenovskikh luchei.

It has been shown that the maxima (Bragg-spacings 4,5-19 A) on the X-ray diffraction patterns of the bovine lens native tissues from nuclear and cortical parts are predominantly due to the water-soluble crystallin intramolecular structure. The structures of water-soluble and water-insoluble fractions from bovine lens nucleus and cortex were qualitatively compared. Reversible dependence of the lens water-soluble protein structure on water content in the system was demonstrated.

[Comparative study of crystallins from the nucleus and cortex of the bovine ocular lens by the gel filtration and x-ray diffraction methods]. / Sravnitel'noe issledovanie kristallinov iadra i korteksa glaza byka metodami gel'-filtratsii i difraktsii rentgenovskikh luchei.

Water--soluble proteins (alpha-, beta H-, beta L- and gamma-crystallins) from the bovine lens nucleus and cortex were fractionated and compared by gel filtration on Sephadex G-200. X-ray diffraction patterns from concentrated gels of these proteins were obtained. It allowed to compare qualitatively the structures of different crystallins and also to identify the maxima on X-ray diffraction patterns of the lens intact tissue.

[Determination of the molecular weight and form of the molecule histidine decarboxylase by the method of small-angle x-ray scattering]. / Opredelenie molekuliarnogo vesa i formy molekuly gistidin-dekarboksilazy metodom rentgenovskogo malouglovogo rasseianiia.

Shape and molecular weight of histidine-decarboxylase from Micrococus sp. n. were studied by the method of X-ray small-angle scattering. The inertion radius of the molecule: Rg-2,93 nm. The shape of the molecule is adequately approximated by rotation ellipsoids of two possible variants: the elongated and flattened ones. The eccentricity in both cases is 1.6. The volume of the enzyme molecule V=190 nm3. The molecular weight of histidine-dexarboxilase obtained from the X-ray experiment M=102 000 c.u.

[Comparative x-ray diffraction study of the crystalline lens in a number of vertebrates including man]. / Sravnitel'noe rentgenovskoe difraktsionnoe issledovanie khrustalikov glaza v riadu pozvonochnykh vkliuchaia cheloveka.

X-ray diffraction method has been applied for comparative investigation of native structure of eye lens proteins (crystallins). X-ray diffraction patterns of the whole lenses and/or their nuclear parts were obtained for man and vertebrate animals. Crystalline lenses of the fishes Acerina cernua and Pelmatochromis kribensis, frog Rana temporaria, bull and man contain crystallins with a very similar secondary and tertiary structure, whereas lenses of chicks and the tortoise Testudo horsfieldi contain mainly crystallins with other structure. The results obtained reveal evolutionary conservatism of crystallin structure in fishes, amphibians and mammals. It was also concluded that there is no correlation between crystallin structure of the lens, elasticity of the latter and accommodation mechanism.

[A structural study of crystallins in the normal and cataractous crystalline lens by x-ray diffraction]. / Strukturnoe issledovanie kristallinov v normal'nom i kataraktal'nom khrustalike metodom difraktsii rentgenovskikh luchei.

Nucleus of the normal and cataractous human lenses were studied by means of the X-ray diffraction method. The conformational changes, as it is shown, take place during cataract formation. The similar as in senile cataract, conformational changes of bovine lens crystallins were induced by UV irradiation.