Department of Botany, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
Plant Physiol. 1985 Mar;77(3):648-52. doi: 10.1104/pp.77.3.648.
Levulinic acid, an inhibitor of porphyrin biosynthesis, causes marked accumulation of a low molecular weight polypeptide in greening maize (Zea mays L.) leaves. Additional compounds which interfere with porphyrin synthesis (e.g. aminooxyacetate, iron-chelators, 4,6-dioxoheptanoic acid) had a similar effect. The polypeptide accumulated in the cytosol and could not be detected in the plastid stroma. Its molecular weight was estimated as 4800 daltons by electrophoresis in sodium dodecyl sulfate-acrylamide gels containing urea and glycerol. The accumulation of the polypeptide did not result from inhibition of chlorophyll or protoheme syntheses. Compounds which caused its accumulation markedly reduced the activity of nitrite reductase. It is suggested that the accumulation is caused by inhibition of siroheme synthesis which interferes with the formation of nitrite or sulfite reductase.
乙酰丙酸是卟啉生物合成的抑制剂，它会导致正在变绿的玉米（Zea mays L.）叶片中低分子量多肽的显著积累。其他干扰卟啉合成的化合物（例如氨基氧乙酸、铁螯合剂、4,6-二氧庚酸）也有类似的效果。该多肽在细胞质中积累，在质体基质中无法检测到。其分子量通过在含有尿素和甘油的十二烷基硫酸钠-丙烯酰胺凝胶中电泳估计为 4800 道尔顿。多肽的积累不是由于叶绿素或原卟啉合成的抑制所致。导致其积累的化合物显著降低了亚硝酸盐还原酶的活性。因此，推测这种积累是由于抑制了干扰亚硝酸盐或亚硫酸还原酶形成的鲨烯合成。
