Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, Ribeirão Preto, São Paulo, Brazil.
Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA.
Arch Biochem Biophys. 2019 Mar 15;663:192-198. doi: 10.1016/j.abb.2019.01.014. Epub 2019 Jan 16.
Tissue-nonspecific alkaline phosphatase (TNAP) is a key enzyme in the biomineralization process as it produces phosphate from a number of phospho-substrates stimulating mineralization while it also inactivates inorganic pyrophosphate, a potent mineralization inhibitor. We have previously reported on the reconstitution of TNAP on Langmuir monolayers as well as proteoliposomes. In the present study, thin films composed of dimyristoylphosphatidic acid (DMPA) were deposited on titanium supports by the Langmuir-Blodgett (LB) technique, and we determined preservation of TNAP's phosphohydrolytic activity after incorporation into the LB films. Increased mineralization was observed after exposing the supports containing the DMPA:TNAP LB films to solutions of phospho-substrates, thus evidencing the role of TNAP on the growth of calcium phosphates after immobilization. These coatings deposited on metallic supports can be potentially applied as osteoconductive materials, aiming at the optimization of bone-substitutes integration in vivo.
组织非特异性碱性磷酸酶（TNAP）是生物矿化过程中的关键酶，因为它可以从多种磷酸底物中产生磷酸，从而刺激矿化，同时还可以使无机焦磷酸酯失活，后者是一种有效的矿化抑制剂。我们之前已经报道了 TNAP 在 Langmuir 单层膜以及蛋白脂质体上的重建。在本研究中，通过 Langmuir-Blodgett（LB）技术将二肉豆蔻酰磷脂酸（DMPA）的薄膜沉积在钛支架上，并确定了将 TNAP 掺入 LB 薄膜后其磷酸水解活性的保留情况。在将含有 DMPA：TNAP LB 薄膜的支架暴露于磷酸底物溶液后，观察到矿化增加，从而证明了 TNAP 在固定化后对磷酸钙生长的作用。这些沉积在金属支架上的涂层可作为潜在的骨传导材料，旨在优化体内骨替代物的整合。
