ISSN:
1615-6102
Keywords:
Cytochromeb 561
;
Ascorbate
;
Plasma membrane
;
Phaseolus vulgaris
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The plasma membrane (PM) of higher plants contains a major ascorbate-reducible, high-potentialb-type cytochrome, named cytochromeb 561 (cytb 561). In this paper a rapid purification protocol for the cytb 561 of bean hypocotyls PM is described. An almost 200-fold increase of cytb 561 specific concentration was achieved with respect to the PM fraction, which contained about 0.2 nmol of ascorbate-reducible heme per mg protein. The procedure can be performed in one day starting from purified PMs obtained by the phase-partitioning procedure. However, cytb 561 proved to be unstable during chromatographic purification and the amount of protein finally recovered was low. Purified cytb 561 eluted as a 130,000 Da protein-detergent complex from gel-filtration columns. It was completely reduced by ascorbate and reduced-minus-oxidized spectra showed α-, β- and γ-bands at 561, 530, and 429 nm respectively, not unlike the spectra of whole PMs. This work represents an initial approach to the biochemical characterization of the cytb 561 of higher plants, formerly suggested to be related to cytb 561 of animal chromaffin granules.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01279295
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