The Molecular Biology Institute, USA.
The Pasarow Mass Spectrometry Laboratory, The Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
Comp Biochem Physiol Part D Genomics Proteomics. 2009 Dec;4(4):305-309. doi: 10.1016/j.cbd.2009.09.001.
The two major apolipoproteins associated with human and chimpanzee (Pan troglodytes) high density lipoproteins (HDL) are apoA-I and dimeric apoA-II. Although humans are closely related to great apes, apolipoprotein data do not exist for bonobos (Pan paniscus), western lowland gorillas (Gorilla gorilla gorilla) and the Sumatran orangutans (Pongo abelii). In the absence of any data, other great apes simply have been assumed to have dimeric apoA-II while other primates and most other mammals have been shown to have monomeric apoA-II. Using mass spectrometry, we have measured the molecular masses of apoA-I and apoA-II associated with the HDL of these great apes. Each was observed to have dimeric apoA-II. Being phylogenetically related, one would anticipate these apolipoproteins having a high percentage of invariant sequences when compared with human apolipoproteins. However, the orangutan, which diverged from the human lineage between 16 and 21 million years ago, had an apoA-II with the lowest monomeric mass, 8031.3 Da and the highest apoA-I value, 28,311.7 Da, currently reported for various mammals. Interestingly, the gorilla that diverged from the lineage leading to the human–chimpanzee branch after the orangutan had almost identical mass values to those reported for human apoA-I and apoA-II. But chimpanzee and the bonobo that diverged more recently had identical apoA-II mass values that were slightly larger than reported for the human apolipoprotein. The chimpanzee A-I mass values were very close to those of humans; however, the bonobo had values intermediate to the molecular masses of orangutan and the other great apes. With the already existing genomic data for chimpanzee and the recent entries for the orangutan and gorilla, we were able to demonstrate a close agreement between our mass spectral data and the calculated molecular weights determined from the predicted primary sequences of the respective apolipoproteins. Post-translational modification of these apolipoproteins, involving truncation and oxidation of methionine, are also reported.
与人（智人）和黑猩猩（Pan troglodytes）高密度脂蛋白（HDL）相关的两种主要载脂蛋白是载脂蛋白 A-I 和二聚体载脂蛋白 A-II。尽管人类与大型猿类密切相关，但尚未有关于倭黑猩猩（Pan paniscus）、西部低地大猩猩（Gorilla gorilla gorilla）和苏门答腊猩猩（Pongo abelii）的载脂蛋白数据。在没有任何数据的情况下，人们只是假设其他大型猿类具有二聚体载脂蛋白 A-II，而其他灵长类动物和大多数其他哺乳动物则具有单体载脂蛋白 A-II。使用质谱法，我们测量了这些大型猿类 HDL 相关的载脂蛋白 A-I 和载脂蛋白 A-II 的分子量。每个都观察到具有二聚体载脂蛋白 A-II。由于在进化上相关，人们预计这些载脂蛋白与人类载脂蛋白相比具有较高比例的不变序列。然而，与人类谱系分化的时间在 1600 万至 2100 万年前的猩猩，其单体质量最低，为 8031.3 Da，载脂蛋白 A-I 值最高，为 28311.7 Da，这是目前各种哺乳动物中报道的最高值。有趣的是，在猩猩之后与人类-黑猩猩谱系分离的大猩猩，其质量值与人类载脂蛋白 A-I 和载脂蛋白 A-II 报道的值几乎相同。但与猩猩相比，与人类-黑猩猩分支分离的时间较近的黑猩猩，其二聚体载脂蛋白 A-II 的质量值略大。黑猩猩的 A-I 质量值非常接近人类的质量值；然而，倭黑猩猩的质量值则处于猩猩和其他大型猿类的质量值之间。由于已经有关于黑猩猩的基因组数据，以及最近关于猩猩和大猩猩的基因组数据，我们能够证明我们的质谱数据与从各自载脂蛋白预测的一级序列计算出的分子量之间存在密切的一致性。这些载脂蛋白的翻译后修饰，包括截短和蛋氨酸氧化，也有报道。
