Shandong Institute of Parasitic Diseases, Shandong First Medical University & Shandong Academy of Medical Sciences, Jining, 272033 Shandong Province, China.
Department of Medical Technology, Jiangsu Vocational College of Medicine, Yancheng, 224006 Jiangsu Province, China.
Biomed Res Int. 2020 Jul 23;2020:6717390. doi: 10.1155/2020/6717390. eCollection 2020.
Aquaporins are a large family of transmembrane channel proteins that facilitate the passive but highly selective transport of water and other small solutes across biological membranes. House dust mite () is the major source of household immunogens, and we have recently reported six cDNA sequence encoding aquaporins from this mite species. To better understand the structure and role of mite aquaporin, we constructed a tertiary structure for DerfAQP1 by homology modeling from the X-ray structure of malaria aquaporin PfAQP (Protein Data Bank code No. 3C02) and conducted molecular dynamics simulation. The simulation arranged seven water molecules in a single file through the pores of the DerfAQP1. Further, two conserved Asn-Pro-Ala motifs were located on Asn203 and Asn77; residues Arg206, Trp57, Met190, Gly200, and Asp207 constituted an extracellular vestibule of the pore; and residues His75, Val80, Ile65, and Ile182 constituted the cytoplasmic portions. The overall free energy profile for water transport through DerfAQP1 revealed an energy barrier of ~2.5 kcal/mol. These results contribute to the understanding of mite physiology and pathology.
水通道蛋白是一大类跨膜通道蛋白，能促进水和其他小溶质在生物膜上的被动但高度选择性运输。屋尘螨是家庭免疫原的主要来源，我们最近报道了从这种螨种中编码 6 种水通道蛋白的 cDNA 序列。为了更好地理解螨类水通道蛋白的结构和功能，我们根据疟原虫水通道蛋白 PfAQP（蛋白数据库编号 3C02）的 X 射线结构，通过同源建模构建了 DerfAQP1 的三级结构，并进行了分子动力学模拟。模拟结果在 DerfAQP1 的孔道中排列了 7 个水分子的单分子通道。此外，两个保守的 Asn-Pro-Ala 基序定位于 Asn203 和 Asn77；残基 Arg206、Trp57、Met190、Gly200 和 Asp207 构成了孔道的细胞外前庭；残基 His75、Val80、Ile65 和 Ile182 构成了细胞质部分。水通过 DerfAQP1 转运的总自由能图谱显示，能量屏障约为 2.5 kcal/mol。这些结果有助于理解螨类的生理学和病理学。
