Phycobilisomes and Isolated Phycobiliproteins. Effect of Glutardialdehyde and Benzoquinone on Fluorescence

Köst, Hans‐Peter; Rath, K.; Wanner, Gerhard; Scheer, Hugo

doi:10.1111/j.1751-1097.1981.tb09337.x

Cited by 1 publication

(1 citation statement)

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“…It should be noted, though, that the uv-vis-* We have achieved the reoxidation of phycorubin with benzoquinone to products identical with PC if judged from absorption, fluorescence and electrophoretical mobilities. Details of this procedure and the reaction of PC with quinones [27] are to be published separately. spectra of bilirubins [28] appear less conformation dependent than those of biliverdins [29].…”

Section: Cooch Coochjmentioning

confidence: 99%

Rubins and Rubinoid Addition Products from Phycocyanin

Kufer¹,

Scheer²

1982

Zeitschrift Für Naturforschung C

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The verdin-type Chromophore of denatured C-phycocyanin (1) from Spirulina platensis is reduced to the corresponding rubin (2a) by sodium borohydride. The structure assigned is in agreement with the uv-vis spectroscopic properties of the product and was deduced from model studies with free bile pigments. Analogous model studies using sodium dithionite demonstrated a two-fold reactivity for this reagent, leading to products which are both o f the rubin spectral type under the conditions tested. True rubins (10,22-dihydrobilindions) are formed in low yield only if an excess of reagent is used in methanol/water mixtures. It is accompanied by polar addition product(s) of the same spectral type, which are generally formed exclusively. In particular, no bilirubin was formed under the reaction conditions previously applied for the chemical modification of phycobiliproteins and phytochrome. From this finding and from the strikingly different properties of the borohydride and dithionite products, of phycocyanin upon renaturation, the dithionite product is suggested to be a rubinoid addition product (2b) rather than a hydrogenation product.In contrast to the dithionite addition product 2b of phycocyanin, the chromophore of the true phycorubin (2a) remains stable upon renaturation. The uv-vis spectral properties of the chromophore are not markedly different whether the apoprotein is in its native or denatured state. The different electrophoretic mobilities of native (renatured) phycocyanin compared to the renatured borohydride product suggest that these two have different protein conformations. The preparation of these phycorubins renders the extensive techniques of bilirubin chemistry applicable in the study of biliproteins.

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Section: Cooch Coochjmentioning

confidence: 99%