Light-dependent degradation

Mouzdahir A. v., Grossi Bakkas S., and Rontani J.-F. (2001) Visible light-dependent degradation of long-chained alkenes in killed cells of Emiliania huxleyi and Nannocchlorpsis salina. Phytochemistry 56, 677-684. 

Gong H. Light-dependent degradation of the phomsys n II Dl protein is retarded by inhibitors of chloroplast transcription and translation A possible involvement of a chloroplast-encoded proteinase. Biochim Biophys Acta 1994 1188 422-426. 

Light dependant degradation of the D1 protein in Cl-depleted thvlakoid membranes. 

Sulfate. As for the production of hydrogen sulfide from sulfur dioxide/sulfite at least three possible pathways for the light-dependent synthesis of hydrogen sulfide in response to sulfate can be assumed, i.e. first the light-dependent reduction of sulfate to carrier-bound sulfide followed by a release of the sulfide moiety from its carrier second the light-dependent reduction of sulfate to carrier-bound sulfide followed by an incorporation of the sulfide moiety into cysteine and subsequent degradation of cysteine third the release of sulfite from carrier-bound sulfite followed by reduction of free sulfite to sulfide (see Figure 1). 

In view of the chemical structure of MDMO-PPV, it is expected that this polymer is very sensitive to solar light. This is attested by several studies that clearly show that oxygen-dependent degradation of the polymer plays a significant role in the failure of devices based on MDMO-PPV [15-18]. Carbonyl defects were shown to have a major influence on devices like PLEDS and the increase of carbonyl defects was correlated to a dramatic reduction of the photoluminescence of the polymer [19,20], Understandings about the origin and the formation of these defects seem relevant in order to improve the stability of the devices based on this kind of polymer. 

Yellowing of the mirrors is light-dependent. When EP/Ag/ glass and PIB/Ag/glass samples were weathered in the dark at 70 C and 50% relative humidity, their mirrors degraded and discolored much more slowly than those weathered in the light (e.g., see Figure 4). 

Light dependent recovery from photoinhibition involves proteolytic degradation of the reaction center protein D1 in photoinactivated PS II centers, and its replacement with newly synthesized D1 polypeptide (3). The absence of trienoic fatty acids in the thylakoid lipids of the mutant/a -2fad8 probably inhibits one or more of the steps involved... 

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