[Membrane-active inhibitors of electron transport in chloroplasts].

The effects of polyene antibiotic amphotericin B and the organophosphorus insecticide chlorophos (trichlorofon) on the electron transport in isolated pea chloroplasts were compared; both compounds were found to inhibit the electron transport. The concentration dependence of the inhibitory effects on the photoreactions in chloroplasts was established. Affer washing of the chloroplasts from amphotericin B admixtures the photoreduction of NADP+ was decreased by 50%, the photooxidation of cytochrome f in situ was affected comparatively little, while the photoreduction of plastocyanin in situ was decreased by 60%.

[The defect in cytochrome c553 in non-photosynthetic mutant cells of Chlamydomonas reinhardii].

The light electron transport in non-photosynthetic mutants of Chlamydomonas reinhardii A-36 and A-68 with a decreased content of cytochrome c553 was studied. The light-induced changes of absorption at 520, 559, 563 nm were shown to occur in the films of intact cells and in cell fragments. However, no maximum of the "light minus dark" difference absorption spectra of mutants belonging to cytochrome c553 was revealed.

[Photo-dependent conversions of cytochrome f in bean chloroplasts and leaves treated with polyene antibiotics].

The photo-dependent absorption changes of cytochrome f in bean chloroplasts and native leaves treated with the polyene antibiotics surgumycin and filipin were studied. Upon incubation of the chloroplasts or leaves with the antibiotics the value of the photo-induced signal of cytochrome f decreased considerably; however, the kinetics of the cytochrome oxidation under the effect of the exciting light and dark reduction remained unchanged. An addition of plastocyanin to the suspension of the antibiotic-treated chloroplasts, which contained no artificial donors and acceptors, only slightly increased the absolute value of the photo-induced signal of cytochrome f.

[Ferredoxin-dependent glutamate synthase of Chlorella].

Ferredoxin-dependent glutamate synthase has been found in cells of thermophylic Chlorella strain Ch. pyrenoidosa 82T. The enzyme is active with its own ferredoxin and that of Spirulina.

[Effect of metalloproteins on the photochemical activity of chloroplasts treated with polyene antibiotics].

The effects of various metall-containing proteins (plastocyanin, plantacyanin, azurine and cytochromes of the f type) on the activity of photosystem I of chloroplasts, treated with polyene antibiotics, were studied. The inhibiting effect of the polyenes, surgumycin and philipin, was completely removed by an addition of copper-containing protein plastocyanin. No similar effect was exerted by other Cu-containing proteins--azurine and plantacyanin.

[Cytochrome f from Chlorella pyrenoidosa Pringsheim 82 T].

Cytochrome of the f type was isolated from the thermophilous autotrophic strain Chlorella pyrenoidosa Pringsheim 82T and purified on Sephadex G-75. The isolation procedure allowed a simultaneous production of glutamate dehydrogenase isoenzymes. From 100 g of Chlorella wet paste 100 to 120 nM of electrophoretically unicomponent protein with a molecular weight of 12,000 to 13,000 were isolated.