Protochlorophyllide b does not occur in barley etioplasts

被引：32

作者：

Scheumann, V ^{[1
]}

Klement, H ^{[1
]}

Helfrich, M ^{[1
]}

Oster, U ^{[1
]}

Schoch, S ^{[1
]}

Rüdiger, W ^{[1
]}

机构：

[1] Univ Munich, Inst Bot, D-80638 Munich, Germany

来源：

FEBS LETTERS | 1999年 / 445卷 / 2-3期

关键词：

chlorophyll biosynthesis; chlorophyllid b; etiolated; NADPH-protochlorophyllide oxidoreductase; (POR); photoconversion; Hordeum;

D O I：

10.1016/S0014-5793(99)00169-6

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Barley (Hordeum vulgare L.) etioplasts were isolated, and the pigments mere extracted with acetone, The extract was analyzed by HPLC. Only protochlorophyllide a and no protochlorophyllide b was detected (limit of detection <1% of protochlorophyllide a). Protochlorophyllide b was synthesized starting from chlorophyll b and incubated with etioplast membranes and NADPH, In the light, photoconversion to chlorophyllide b was observed, apparently catalyzed by NADPH:protochlorophyllide oxidoreductase. In darkness, reduction of the analogue zinc protopheophorbide b to zinc 7(1)-hydroxy-protopheophorbide a was observed, apparently catalyzed by chlorophyll b reductase. We conclude that protochlorophyllide b does not occur in detectable amounts in etioplasts, and even traces of it as the free pigment are metabolically unstable. Thus the direct experimental evidence contradicts the idea by Reinbothe et al, (Nature 397 (1999) 80-84) of a protochlorophyllide b-containing light-harvesting complex in barley etioplasts. (C) 1999 Federation of European Biochemical Societies.

引用

页码：445 / 448

页数：4

共 15 条

[1]

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[2] Cryopreservation of chlorophyll synthesis and apoprotein stabilization in barley etioplasts [J].