Valueva Anastasiya V, Romanov Roman S, Vorobyeva Nataliya N, Kurilova Svetlana A, Rodina Elena V
Pharmaceutical Department, Pavlov Ryazan State Medical University, 9 Vysokovol'tnaya Street, Ryazan 390026, Russia.
Department of Fundamental Medicine, Lomonosov Moscow State University, 31, Build. 5, Lomonosovsky Prospect, Moscow 119991, Russia.
ACS Omega. 2020 Mar 20;5(12):6641-6650. doi: 10.1021/acsomega.9b04428. eCollection 2020 Mar 31.
Pyrophosphate arthropathy is the mineralization defect in humans caused by the deposition of microcrystals of calcium pyrophosphate dihydrate in joint tissues. As a potential therapeutic strategy for the treatment of pyrophosphate arthropathy, delivery of exogenous pyrophosphate-hydrolyzing enzymes, inorganic pyrophosphatases (PPases), to the synovial fluid has been suggested. Previously, we synthesized the conjugates of PPase (Ec-PPase) with detonation synthesis nanodiamonds (NDs) as a delivery platform, obtaining the hybrid biomaterial retaining high pyrophosphate-hydrolyzing activity in vitro. However, most known PPases including Ec-PPase in the soluble form are strongly inhibited by Ca ions. Because synovial fluid contains up to millimolar concentrations of soluble calcium, this inhibition might limit the in vivo application of Ec-PPase-based material in joint tissues. In this work, we proposed other bacterial PPases from (Mt-PPase), which are resistant to the inhibition by Ca ions, as an active PP-hydrolyzing agent. We synthesized conjugates of Mt-PPase with NDs and tested their activity under various conditions. Unexpectedly, conjugates of both Ec-PPase and Mt-PPase with aminated NDs retained significant hydrolytic activity in the presence of well-known mechanism-based PPase inhibitors, fluoride or calcium. The incomplete inhibition of PPases by fluoride or calcium was found for the first time.
焦磷酸关节病是由二水合焦磷酸钙微晶在关节组织中沉积引起的人类矿化缺陷。作为治疗焦磷酸关节病的一种潜在治疗策略，有人提出将外源性焦磷酸水解酶，即无机焦磷酸酶（PPases）输送到滑液中。此前，我们合成了PPase（Ec-PPase）与爆轰合成纳米金刚石（NDs）的缀合物作为递送平台，得到了在体外保留高焦磷酸水解活性的杂化生物材料。然而，大多数已知的PPases，包括可溶性形式的Ec-PPase，都受到钙离子的强烈抑制。由于滑液中含有高达毫摩尔浓度的可溶性钙，这种抑制作用可能会限制基于Ec-PPase的材料在关节组织中的体内应用。在这项工作中，我们提出了来自[具体来源未给出]的其他细菌PPases（Mt-PPase），它们对钙离子的抑制具有抗性，作为一种活性PP水解剂。我们合成了Mt-PPase与NDs的缀合物，并在各种条件下测试了它们的活性。出乎意料的是，Ec-PPase和Mt-PPase与胺化NDs的缀合物在存在著名的基于机制的PPase抑制剂氟化物或钙的情况下仍保留了显著的水解活性。首次发现氟化物或钙对PPases的抑制不完全。
