Benevides Leandro de Jesus, Carvalho Daniel Santana de, Andrade Roberto Fernandes Silva, Bomfim Gilberto Cafezeiro, Fernandes Flora Maria de Campos
Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil.
Universidade Federal da Bahia (UFBA), Salvador, BA, Brazil.
Genet Mol Biol. 2016 Oct-Dec;39(4):665-673. doi: 10.1590/1678-4685-GMB-2015-0164. Epub 2016 Jul 14.
Apolipoprotein E (apo E) is a human glycoprotein with 299 amino acids, and it is a major component of very low density lipoproteins (VLDL) and a group of high-density lipoproteins (HDL). Phylogenetic studies are important to clarify how various apo E proteins are related in groups of organisms and whether they evolved from a common ancestor. Here, we aimed at performing a phylogenetic study on apo E carrying organisms. We employed a classical and robust method, such as Maximum Likelihood (ML), and compared the results using a more recent approach based on complex networks. Thirty-two apo E amino acid sequences were downloaded from NCBI. A clear separation could be observed among three major groups: mammals, fish and amphibians. The results obtained from ML method, as well as from the constructed networks showed two different groups: one with mammals only (C1) and another with fish (C2), and a single node with the single sequence available for an amphibian. The accordance in results from the different methods shows that the complex networks approach is effective in phylogenetic studies. Furthermore, our results revealed the conservation of apo E among animal groups.
载脂蛋白E（apo E）是一种含有299个氨基酸的人类糖蛋白，它是极低密度脂蛋白（VLDL）和一组高密度脂蛋白（HDL）的主要成分。系统发育研究对于阐明不同的载脂蛋白E蛋白在生物群体中是如何关联的，以及它们是否起源于一个共同的祖先非常重要。在这里，我们旨在对携带载脂蛋白E的生物体进行系统发育研究。我们采用了一种经典且可靠的方法，如最大似然法（ML），并使用基于复杂网络的更新方法比较结果。从NCBI下载了32个载脂蛋白E氨基酸序列。在三个主要群体之间可以观察到明显的区分：哺乳动物、鱼类和两栖动物。从最大似然法以及构建的网络获得的结果显示出两个不同的群体：一个仅包含哺乳动物（C1），另一个包含鱼类（C2），还有一个单独的节点包含仅有的一个两栖动物序列。不同方法结果的一致性表明，复杂网络方法在系统发育研究中是有效的。此外，我们的结果揭示了动物群体中载脂蛋白E的保守性。
