Background: It has been previously found that PrP_23-98, which contains four highly conserved octarepeats (residues 60-91) and one partial repeat (residues 92-96), polymerizes into amyloid-like and proteinase K-resistant spherical aggregates in the presence of NADPH plus copper ions.

Objective: We aimed to determine the requirements for the formation of these aggregates.

Methods: In this study, we performed an aggregation experiment using N-acetylated and Camidated PrP fragments of the N-terminal domain, Octa1, Octa2, Octa3, Octa4, PrP₈₄₋₁₁₄, and PrP₇₆₋₁₁₄, in the presence of NADPH with copper ions, and focused on the effect of the number of copper-binding sites on aggregation.

Results: Among these PrP fragments, Octa4, containing four copper-binding sites, was particularly effective in forming aggregates. We also tested the effect of other pyridine nucleotides and adenine nucleotides on the aggregation of Octa4. ATP was equally effective, but NADH, NADP, ADP, and AMP had no effect.

Conclusion: The phosphate group on the adenine-linked ribose moiety of adenine nucleotides and pyridine nucleotides is presumed to be essential for the observed effect on aggregation. Efficient aggregation requires the presence of the four octarepeats. These insights may be helpful in the eventual development of therapeutic agents against prion-related disorders.

背景：先前已经发现，PrP _23-98包含四个高度保守的八角豆（残基60-91）和一个部分重复（残基92-96），在其内部聚合成淀粉样蛋白和耐蛋白酶K的球形聚集体。 NADPH加铜离子的存在。

目的：我们旨在确定形成这些骨料的要求。

方法：在这项研究中，我们在存在NADPH的情况下，使用N末端结构域Octa1，Octa2，Octa3，Octa4，PrP _84-114和PrP _76-114的N-乙酰化和Camidated PrP片段进行了聚集实验与铜离子结合，并着重于铜结合位点数目对聚集的影响。

结果：在这些PrP片段中，含有四个铜结合位点的Octa4在形成聚集体方面特别有效。我们还测试了其他吡啶核苷酸和腺嘌呤核苷酸对Octa4聚集的影响。ATP同样有效，但是NADH，NADP，ADP和AMP无效。

结论：腺嘌呤核苷酸和吡啶核苷酸的腺嘌呤连接的核糖部分上的磷酸基团被认为对于观察到的聚集效应至关重要。有效的聚集需要四个八角豆的存在。这些见解可能有助于最终开发针对病毒相关疾病的治疗剂。