Disulfide-dependent self-assembly of adiponectin octadecamers from trimers and presence of stable octadecameric adiponectin lacking disulfide bonds in vitro.
Disulfide-dependent self-assembly of adiponectin octadecamers from trimers and presence of stable octadecameric adiponectin lacking disulfide bonds in vitro.
复制标题
DOI：
10.1021/bi9015555
复制
发表时间：
2009-12-29
期刊：
影响因子：
2.9
通讯作者：
Tsao, Tsu-Shuen
中科院分区：
文献类型：
--
作者：
Briggs, David B.;Jones, Christopher M.;Mashalidis, Ellene H.;Nunez, Martha;Hausrath, Andrew C.;Wysocki, Vicki H.;Tsao, Tsu-Shuen
脂联素是一种循环中的胰岛素增敏激素，可同源寡聚成三聚体、六聚体和高分子量（HMW）物质。低水平的循环高分子量脂联素似乎会增加胰岛素抵抗的风险。目前，脂联素寡聚体的组装以及因此导致胰岛素抵抗中HMW脂联素降低的机制还不清楚。在本文报告的工作中，我们分析了最丰富的HMW脂联素物质十八聚体在体外分解为较小的低聚物后的重新组装。纯化的牛血清脂联素十八聚体在pH 5下用还原剂处理以获得三聚体。这些还原的三聚体在氧化形成二硫键后部分自发地重新组装成十八聚体。二硫键似乎在低聚过程中比在成熟十八聚体的结构稳定中占据更大的作用。使用天然凝胶电泳、动态光散射和碰撞诱导解离纳米电喷雾电离质谱法，可以大量观察到缺乏几乎所有二硫键的稳定十八聚体。这些发现表明，虽然二硫键有助于维持成熟的十八聚体脂联素结构，但它们更重要的功能是稳定十八聚体组装过程中的中间体。脂联素寡聚化必须通过至少部分还原的中间体进行。因此，完全氧化的脂联素六聚体不能以与还原的三聚体相当的速率重新组装成十八聚体。由于本研究的结果基于体外实验，因此其体内相关性仍不清楚。然而，他们描述了一种氧化还原环境依赖的脂联素寡聚化模型，可以使用基于细胞的方法进行测试。
Adiponectin is a circulating insulin-sensitizing hormone that homo-oligomerizes into trimers, hexamers, and higher molecular weight (HMW) species. Low levels of circulating HMW adiponectin appear to increase the risk for insulin resistance. Currently, assembly of adiponectin oligomers, and consequently mechanisms responsible for decreased HMW adiponectin in insulin resistance, are not well understood. In the work reported here, we analyzed the re-assembly of the most abundant HMW adiponectin species, the octadecamer, following its collapse to smaller oligomers in vitro. Purified bovine serum adiponectin octadecamer was treated with reducing agents at pH 5 to obtain trimers. These reduced trimers partially and spontaneously reassembled into octadecamers upon oxidative formation of disulfide bonds. Disulfide bonds appear to occupy a greater role in the process of oligomerization than in the structural stabilization of mature octadecamer. Stable octadecamers lacking virtually all disulfide bonds could be observed in abundance using native gel electrophoresis, dynamic light scattering, and collision-induced dissociation nano-electrospray ionization mass spectrometry. These findings indicate that while disulfide bonds help to maintain the mature octadecameric adiponectin structure, their more important function is to stabilize intermediates during the assembly of octadecamer. Adiponectin oligomerization must proceed through intermediates that are at least partially reduced. Accordingly, fully oxidized adiponectin hexamers failed to reassemble into octadecamers at a rate comparable to that of reduced trimers. As the findings from the present study are based on in vitro experiments, their in vivo relevance remains unclear. Nevertheless, they describe a redox environment-dependent model of adiponectin oligomerization that can be tested using cell-based approaches.
登录
查看更多内容
影响因子：
56.9
作者：
HWANG, C;SINSKEY, AJ;LODISH, HF
通讯作者：
LODISH, HF
DOI：
10.1152/ajpendo.00187.2006
发表时间：
2006-11-01
影响因子：
5.1
作者：
Bodles, Angela M.;Banga, Anannya;Owens, Randall J.
通讯作者：
Owens, Randall J.
影响因子：
82.9
作者：
Maeda, N;Shimomura, I;Matsuzawa, Y
通讯作者：
Matsuzawa, Y
影响因子：
4.8
作者：
Combs, TP;Pajvani, UB;Scherer, PE
通讯作者：
Scherer, PE
影响因子：
4.8
作者：
Nawrocki, AR;Rajala, MW;Scherer, PE
通讯作者：
Scherer, PE