The marine picocyanobacteria Synechococcus and Prochlorococcus numerically dominate open ocean phytoplankton. Although evolutionarily related they are ecologically distinct, with different strategies to harvest, manage and exploit light. We grew representative strains of Synechococcus and Prochlorococcus and tracked their susceptibility to photoinactivation of Photosystem II under a range of li...

The photoinactivation of complement has been studied with a view to determining if possible how many kinds of molecules disappeared during the reaction. It was found that: 1. The apparent course of photoinactivation is that of a monomolecular reaction. 2. Diffusion is not the limiting factor responsible for this fact, because the temperature coefficient of diffusion is much higher than that of ...

Lincomycin-treated pumpkin leaves were illuminated with either continuous light or saturating single-turnover xenon flashes to study the dependence of photoinactivation of photosystem II (PSII) on the mode of delivery of light. The flash energy and the time interval between the flashes were varied between the experiments, and photoinactivation was measured with oxygen evolution and the ratio of...

BACKGROUND Among the most prominent molecular constituents of a recycling synaptic vesicle is the clathrin triskelion, composed of clathrin light chain (Clc) and clathrin heavy chain (Chc). Remarkably, it remains unknown whether clathrin is strictly necessary for the stimulus-dependent re-formation of a synaptic vesicle and, conversely, whether clathrin-independent vesicle endocytosis exists at...

Field studies in fresh and marine waters consistently show diel fluctuations in concentrations of enterococci, indicators of water quality. We investigated sunlight inactivation of Enterococcus faecalis to gain insight into photoinactivation mechanisms and cellular responses to photostress. E. faecalis bacteria were exposed to natural sunlight in clear, filtered seawater under both oxic and ano...

Rose Bengal is a potent inhibitor of 6-phosphogluconate dehydrogenase from Candida utilis and mediates the photoinactivation of the enzyme. The experiments reported in this paper indicate that photoinactivation occurs only when the dye is bound to the TPN binding site of the enzyme. Since the photoinactivation is correlated to the specific oxidation of only 2 residues of histidine, it can be as...

The effect o f exposure to strong white light on photosynthetic electron transport reactions o f PS I and PS II were investigated in spinach thylakoids in the absence or presence o f oxygen. Irrespective o f the conditions used for photoinactivation, the damage to PS II was always much more than to PS I. Photoinactivation was severe under anaerobic conditions compared to that in air for the sam...

Cells of the established line NHIK 3025 were incubated with hematoporphyrin derivative and exposed to light at different concentrations of oxygen. The efficiency of photoinactivation of the sensitized cells decreased with decreasing oxygen concentration. No photoinactivation was observed when the atmosphere above the medium overlying the cells was pure N2 gas. With 1% O2 in the atmosphere, the ...

36 male patients with genital infection by HSV confirmed by culture were each allocated to one of three treatment groups: (1) Proflavine photoinactivation, (2) 0.5 per cent. idoxuridine ointment (IDU), (3) Normal saline. They were assessed objectively at each attendance by measurement of the lesions with an operating microscope fitted with a measuring grid in one eyepiece. Material for culture ...

FAD photosensitizes its own oxidation and that of D-amino acid oxidase. First order photoinactivation of the enzyme is paraIieIed by losses of cysteine, histidine, tyrosine, lysine, and, at saturating levels of FAD, tryptophan. Minimal photo-oxidation of methionine has also been found with illuminated enzyme samples. Native and partially photoinactivated enzyme have the same pH activity profile...