ISSN:
1432-2048
Keywords:
Cucurbita
;
Endoplasmic reticulum
;
Light (blue) receptor
;
Plasmalemma
;
Riboflavin binding
;
Zea
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Saturable and reversible in vitro binding of [14C]riboflavin was found to occur on subcellular, sedimentable particles from maize coleoptiles and Cucurbita hypocotyls. The KD was ca. 6 μM, the pH optimum was near 6.0, and the number of binding sites amounted to 0.1–0.5 μM on a fresh-weight basis. When the reducing agent dithionite was present, riboflavin binding increased-the KD was 2.5 μM, and the pH optimum above 8.0. The binding was specific: flavin mononucleotide (FMN) and flavin adenosine-dinucleotide (FAD) bound less tightly to these sites than riboflavin and another major soluble flavin, the previously described riboflavin-analog “FX”, occurring in grass coleoptiles. These flavin-binding sites were localized on vesicles derived from plasmalemma and endoplasmic reticulum by analyzing sucrose and metrizamide density gradients and marker enzymes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00379839
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