Reduction of exogenous cytochrome c by Neurospora crassa conidia: effects of superoxide dismutase and blue light.
The reduction of externally added cytochrome c by Neurospora crassa conidia was observed. The reduction was stimulated by antimycin A and suppressed partially by superoxide dismutase. When conidia were treated with diethyldithiocarbamate, which inactivated endogenous superoxide dismutase, the cytochrome c reduction was stimulated. Blue light also stimulated the cytochrome c reduction. Azide, which inhibits photochemical reactions mediated by flavins, suppressed the blue light effect. Superoxide dismutase partially suppressed the cytochrome c reduction in the light. The results suggest that O2(-) participates in the cytochrome c reduction by conidia and the flavins or flavoproteins are candidates for the receptor pigment of blue light to stimulate the cytochrome c reduction. It was also suggested that the redox component(s), which could directly transfer its reducing equivalents to exogenous cytochrome c, was present at the surface of conidia.
D000693:Anaerobiosis; D000968:Antimycin A / Q000494:pharmacology; D001386:Azides / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism*; D005415:Flavins / Q000502:physiology; D005420:Flavoproteins / Q000502:physiology; D007700:Kinetics; D008027:Light; D009491:Neurospora / Q000378:metabolism*; D009492:Neurospora crassa / Q000378:metabolism* / Q000528:radiation effects; D010084:Oxidation-Reduction; D019810:Sodium Azide; D013172:Spores, Fungal / Q000378:metabolism; D013482:Superoxide Dismutase / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism
D001386:Azides; D003574:Cytochrome c Group; D005415:Flavins; D005420:Flavoproteins; D013481:Superoxides; D000968:Antimycin A; D019810:Sodium Azide; D013482:Superoxide Dismutase