Most commonly small outer membrane proteins, possessing between 8 and 12 β-strands, are not involved in transport but fulfill diverse functions such as cell adhesion or binding of ligands. An intriguing exception are the 8-stranded β-barrel proteins of the OmpW family, which are implicated in the transport of small molecules. A representative example is AlkL from Pseudomonas putida GPoI, which functions as a passive importer of hydrophobic molecules. This role is of high interest with respect to both fundamental biological understanding and industrial applications in biocatalysis, since this protein is frequently utilized in biotransformation of alkanes. While the transport function of AlkL is generally accepted, a controversy in the transport mechanism still exists. In order to address this, we are pursuing a structural study of recombinantly produced AlkL reconstituted in lipid bilayers using solid-state NMR spectroscopy. In this manuscript we present ¹H, ¹³C and ¹⁵N chemical shift assignments obtained via a suite of 3D experiments employing high magnetic fields (1 GHz and 800 MHz) and the latest magic-angle spinning (MAS) approaches at fast (60–111) kHz rates. We additionally analyze the secondary structure prediction in comparison with those of published structures of homologous proteins.

中文翻译：

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通过质子检测固态 NMR 对脂质双层中外膜蛋白 AlkL 的共振分配。

最常见的小外膜蛋白，拥有 8 到 12 条 β 链，不参与运输，但具有多种功能，例如细胞粘附或配体结合。一个有趣的例外是 OmpW 家族的 8 链 β-桶蛋白，它们与小分子的转运有关。一个代表性的例子是来自恶臭假单胞菌 GPoI 的 AlkL，作为疏水分子的被动进口者。这种作用对于生物催化的基本生物学理解和工业应用都具有重要意义，因为这种蛋白质经常用于烷烃的生物转化。虽然 AlkL 的转运功能已被普遍接受，但其转运机制仍存在争议。为了解决这个问题，我们正在使用固态核磁共振光谱对重组生产的 AlkL 进行脂质双层重组的结构研究。在这份手稿中，我们提出了¹ H、¹³ C 和¹⁵通过一系列采用高磁场（1 GHz 和 800 MHz）的 3D 实验和最新的魔角旋转 (MAS) 方法以快速 (60–111) kHz 速率获得 N 化学位移分配。我们还分析了与已发表的同源蛋白质结构的二级结构预测。