Nourse A, Treacy G B, Shaw D C, Jeffrey P D
Division of Biochemistry and Molecular Biology, Australian National University, Canberra.
Biol Chem Hoppe Seyler. 1996 Feb;377(2):147-53. doi: 10.1515/bchm3.1996.377.2.147.
Insulin from a monotreme, the platypus (Ornithorhynchus anatinus), was isolated and the amino acid sequence determined. It differs from pig insulin at eleven amino acid sites, mainly on the surface of the monomer. Substitutions relative to pig insulin occur in the monomer-monomer interface, the dimer-dimer interface and the receptor binding region. The residues A5 Glu, A8 Lys and A13 Met have not been reported before in any insulin. Multiple sequence comparison studies reveal a relatively close relationship with the nearest group of relatives to the platypus, the mammals. The relationship of the platypus sequence to reptilian insulin sequences (and amphibian and avian insulin sequences in this case) is sufficiently close to support the observation that platypus has retained some ancient reptilian characteristics over the course of evolution. Model building the platypus insulin sequence on the structure of porcine insulin indicates that there may be some interesting differences.
从单孔目动物鸭嘴兽（Ornithorhynchus anatinus）中分离出胰岛素，并确定了其氨基酸序列。它在11个氨基酸位点上与猪胰岛素不同，主要位于单体表面。相对于猪胰岛素的替换发生在单体 - 单体界面、二聚体 - 二聚体界面和受体结合区域。残基A5 Glu、A8 Lys和A13 Met在任何胰岛素中均未被报道过。多序列比较研究表明，它与鸭嘴兽最近的亲属类群——哺乳动物有相对密切的关系。鸭嘴兽胰岛素序列与爬行动物胰岛素序列（以及在这种情况下的两栖动物和鸟类胰岛素序列）的关系足够密切，足以支持这样的观察结果：鸭嘴兽在进化过程中保留了一些古老的爬行动物特征。基于猪胰岛素结构构建鸭嘴兽胰岛素序列模型表明，可能存在一些有趣的差异。
