Department of Biology, Nuclear Research Center "Demokritos," Athens, Greece.
Plant Physiol. 1976 Jul;58(1):43-6. doi: 10.1104/pp.58.1.43.
The enzymic nature of the protein moiety of protochlorophyll(ide) holochrome was studied by following the fate of the [(14)C]protochlorophyll(ide) formed when dark-grown barley (Hordeum vulgare) or bean (Phaseolus vulgaris) leaves are incubated in the dark with 3 mm 4-delta-[(14)C]aminolevulinic acid. It was found that: [List: see text]Since turnover of protochlorophyll(ide) was not observed, these results show that there is a free exchange between the old "endogenous" and the new delta-aminolevulinic-acid-induced protochlorophyll(ide) molecules on the active site of the holochrome protein. These results are consistent with the hypothesis that the holochrome protein acts as an enzyme.
原叶绿素(原卟啉)全色素蛋白部分的酶性质,是通过研究暗培养的大麦(Hordeum vulgare)或菜豆(Phaseolus vulgaris)叶片在暗处与 3mm4-δ-[(14)C]氨基酮戊酸一起孵育时形成的[(14)C]原叶绿素(原卟啉)的命运来研究的。结果发现:[列表:见正文]由于原叶绿素(原卟啉)没有周转,这些结果表明,在全色素蛋白的活性部位,旧的“内源性”和新的δ-氨基酮戊酸诱导的原叶绿素(原卟啉)分子之间存在自由交换。这些结果与全色素蛋白作为酶起作用的假说一致。