Structure of nuclear chromatin in cells of lymphoid organs and blood from mice maintained under abnormal light-dark cycle and treated with benz(a)pyrene.

We studied the effects of benzo(a)pyrene on lymphocyte chromatin in mice with experimental desynchronosis. Desynchronosis altered chromatin structure in immune system cells and suppressed the immune response. In mice with experimental desynchronosis, benzo(a)pyrene produced more pronounced changes in the chromatin structure compared to the control. It was inferred that light-dark cycle disturbances impair the resistance of organs and systems to damaging environmental factors.

[Comparative study of light-harvesting complexes of purple photosynthetic bacteria Chromatium minutissimum and Rhodopseudomonas palustris]. / Sravnitel'noe izuchenie svetosobiraiushchikh kompleksov purpurnykh fotosinteziruiushchikh bakterii Chromatium minutissimum i Rhodopseudomonas palustris.

Light-harvesting pigment-lipoprotein complexes from sulfur (Chromatium minutissimum) and non-sulfur (Rhodopseudomonas palustris) purple bacteria are isolated and comparatively studied. Electron microscopy was used for determination of the complex size, different methods were employed to estimate their molecular weights and chemical composition. Two small proteins are found in each complex, their molecular weight, molar ratio and their content per complex being studied. Amino acid composition and N-terminal amino acids are determined for both proteins of light-harvesting complex from Chromatium minutissimum. Some common characteristics of the molecular organization of light-harvesting complexes in purple bacteria are discussed.