Organisms use proteins such as statherin to control the growth of hydroxyapatite (HAP), which is the principal component of teeth and bone. Though much emphasis has been placed on the acidic character of these proteins, the role of their basic amino acids is not well understood. In this work, solid state nuclear magnetic resonance was used to probe the interaction of the basic arginine side chains with the HAP surface. Statherin samples were individually labeled at each arginine site, and the distance to the surface was measured using the Rotational Echo DOuble Resonance (REDOR) technique. The results indicate a strong coupling between the R9 and R10 residues and the phosphorus atoms on the surface, with internuclear distances of 4.62 ± 0.29 Å and 4.53 ± 0.16 Å, respectively. Conversely, results also indicate weak coupling between R13 and the surface, suggesting this residue is more removed from the surface than R9 and R10. Combining these results with previous data, a new model for the molecular recognition of HAP by statherin is constructed.

中文翻译：

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使用固态核磁共振研究碱性氨基酸在富酪蛋白分子识别羟基磷灰石中的作用


生物体利用富酪蛋白等蛋白质来控制羟基磷灰石 (HAP) 的生长，羟基磷灰石是牙齿和骨骼的主要成分。尽管人们非常重视这些蛋白质的酸性特征，但它们的碱性氨基酸的作用尚不清楚。在这项工作中，固态核磁共振被用来探测碱性精氨酸侧链与HAP表面的相互作用。 Statherin 样品在每个精氨酸位点进行单独标记，并使用旋转回波双共振 (REDOR) 技术测量到表面的距离。结果表明，R9 和 R10 残基与表面上的磷原子之间存在强耦合，核间距分别为 4.62 ± 0.29 Å 和 4.53 ± 0.16 Å。相反，结果还表明 R13 和表面之间的耦合较弱，表明该残留物比 R9 和 R10 从表面上去除得更多。将这些结果与之前的数据相结合，构建了富酪蛋白对 HAP 分子识别的新模型。