Shingles Richard, Wimmers Larry E, McCarty Richard E
Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218-2685, USA.
Plant Physiol. 2004 May;135(1):145-51. doi: 10.1104/pp.103.037895. Epub 2004 Apr 30.
The initial rate of Cu2+ movement across the thylakoid membrane of pea (Pisum sativum) chloroplasts was directly measured by stopped-flow spectrofluorometry using membranes loaded with the Cu(2+)-sensitive fluorophore Phen Green SK. Cu2+ transport was rapid, reaching completion within 0.5 s. The initial rate of uptake was dependent upon Cu2+ concentration and saturated at about 0.6 microm total Cu2+. Cu2+ uptake was maximal at a thylakoid lumen pH of 7.0. Cu2+ transport was inhibited by Zn2+ but was largely unaffected by Mn2+ and Cu+. Zn2+ inhibited Cu2+ transport to a maximum of 60%, indicating that there may be more than one transporter for copper in pea thylakoid membranes.
通过使用负载有铜离子敏感荧光团吩嗪绿SK的类囊体膜，采用停流荧光光谱法直接测定了铜离子穿过豌豆（Pisum sativum）叶绿体类囊体膜的初始速率。铜离子转运迅速，在0.5秒内完成。摄取的初始速率取决于铜离子浓度，在总铜离子浓度约为0.6微摩尔时达到饱和。在类囊体腔pH值为7.0时，铜离子摄取量最大。锌离子抑制铜离子转运，但锰离子和铜离子对其影响不大。锌离子对铜离子转运的抑制作用最大可达60%，这表明豌豆类囊体膜中可能存在不止一种铜离子转运体。
