Boyd D, Vecoli C, Belcher D M, Jain S K, Drysdale J W
J Biol Chem. 1985 Sep 25;260(21):11755-61.
We have isolated essentially full-length cDNA clones for human ferritin H and L chains from a human liver cDNA library. This allows the first comparison of H and L nucleotide and amino acid sequences from the same species as well as ferritin L cDNA sequences from different species. We conclude that human H and L ferritins are related proteins which diverged about the time of evolution of birds and mammals. We also deduce the secondary structure of the H and L subunits and compare this with the known structure of horse spleen ferritin. We find that residues involved in subunit interaction in shell assembly are highly conserved in H and L sequences. However, we find several interesting differences in H subunits at the amino acid residues involved in iron transport and deposition. These substitutions could account for known differences in the uptake, storage, and release of iron from isoferritins of different subunit composition.
我们从人肝脏cDNA文库中分离出了人铁蛋白H链和L链的基本全长cDNA克隆。这使得首次能够比较来自同一物种的H链和L链的核苷酸及氨基酸序列，以及来自不同物种的铁蛋白L cDNA序列。我们得出结论，人H型和L型铁蛋白是相关蛋白，它们在鸟类和哺乳动物进化时期左右发生了分化。我们还推导了H亚基和L亚基的二级结构，并将其与马脾铁蛋白的已知结构进行比较。我们发现，在外壳组装中参与亚基相互作用的残基在H链和L链序列中高度保守。然而，我们在参与铁转运和沉积的氨基酸残基处发现了H亚基中的几个有趣差异。这些取代可能解释了不同亚基组成的异铁蛋白在铁摄取、储存和释放方面的已知差异。
