Fachbereich Biologie, Universität Kaiserslautern, Pfaffenbergstraße, D-6750, Kaiserslautern, Federal Republic of Germany.
Planta. 1979 Jan;145(1):95-104. doi: 10.1007/BF00379933.
Two isoenzymes each of glucosephosphate isomerase (EC 5.3.1.9), phosphoglucomutase (EC 2.7.5.1), glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.43) were separated by (NH4)2SO4 gradient solubilization and DEAE-cellulose ion-exchange chromatography from green leaves of the C3-plants spinach (Spinacia oleracea L.), tobacco (Nicotiana tabacum L.) and wheat (Triticum aestivum L.), of the Crassulacean-acid-metabolism plants Crassula lycopodioides Lam., Bryophyllum calycinum Salisb. and Sedum rubrotinctum R.T. Clausen, and from the green algae Chlorella vulgaris and Chlamydomonas reinhardii. After isolation of cell organelles from spinach leaves by isopyenic centrifugation in sucrose gradients one of two isoenzymes of each of the four enzymes was found to be associated with whole chloroplasts while the other was restricted to the soluble cell fraction, implying the same intracellular distribution of these isoenzymes also in the other species.Among C4-plants, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were found in only one form in corn (Zea mays L.), sugar cane (Saccharum officinarum L.) and Coix lacrymajobi L., but as two isoenzymes in Atriplex spongiosa L. and Portulaca oleracea L. In corn, the two dehydrogenases were mainly associated with isolated mesophyll protoplasts while in Atriplex spongiosa they were of similar specific activity in both mesophyll protoplasts and bundle-sheath strands. In all five C4-plants three isoenzymes of glucosephosphate isomerase and phosphoglucomutase were found. In corn two were localized in the bundle-sheath strands and the third one in the mesophyll protoplasts. The amount of activity of the enzymes was similar in each of the two cell fractions. Apparently, C4 plants have isoenzymes not only in two cell compartments, but also in physiologically closely linked cell types such as mesophyll and bundle-sheath cells.
两种同工酶的磷酸葡萄糖异构酶（EC 5.3.1.9）、磷酸葡萄糖变位酶（EC 2.7.5.1）、葡萄糖-6-磷酸脱氢酶（EC 1.1.1.49）和 6-磷酸葡萄糖酸脱氢酶（EC 1.1.1.43）分别通过（NH4）2SO4 梯度溶解和 DEAE-纤维素离子交换层析从 C3 植物菠菜（Spinacia oleracea L.）、烟草（Nicotiana tabacum L.）和小麦（Triticum aestivum L.）、景天酸代谢植物落地生根（Bryophyllum calycinum Salisb.）、石莲花（Crassula lycopodioides Lam.）和景天（Sedum rubrotinctum R.T. Clausen）、绿藻小球藻（Chlorella vulgaris）和莱茵衣藻（Chlamydomonas reinhardii）的绿色叶片中分离得到。通过等密度离心在蔗糖梯度中分离菠菜叶片细胞器官后，发现四种酶中的每一种的两种同工酶之一与完整的叶绿体相关，而另一种同工酶则局限于可溶细胞部分，这表明这些同工酶在其他物种中也具有相同的细胞内分布。在 C4 植物中，只有在玉米（Zea mays L.）、甘蔗（Saccharum officinarum L.）和薏苡（Coix lacrymajobi L.）中发现葡萄糖-6-磷酸脱氢酶和 6-磷酸葡萄糖酸脱氢酶只有一种形式，而在滨藜（Atriplex spongiosa L.）和马齿苋（Portulaca oleracea L.）中则有两种同工酶。在玉米中，两种脱氢酶主要与分离的叶肉原生质体相关，而在滨藜中，两种同工酶在叶肉原生质体和束鞘纤维中具有相似的比活性。在所有 5 种 C4 植物中，发现了 3 种磷酸葡萄糖异构酶和磷酸葡萄糖变位酶同工酶。在玉米中，两种同工酶定位于束鞘纤维中，第三种同工酶定位于叶肉原生质体中。这些酶的活性在两个细胞部分中相似。显然，C4 植物不仅在两个细胞隔室中具有同工酶，而且在生理上密切相关的细胞类型（如叶肉和束鞘细胞）中也具有同工酶。
