Detection of hydroxyl ions in bone mineral by solid-state NMR spectroscopy
Detection of hydroxyl ions in bone mineral by solid-state NMR spectroscopy
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DOI：
10.1126/science.1078470
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发表时间：
2003-05-16
期刊：
影响因子：
56.9
通讯作者：
Ackerman, JL
中科院分区：
文献类型：
--
作者：
Cho, GY;Wu, YT;Ackerman, JL
先前对骨矿物质磷酸钙晶体的羟基（OH-）离子含量的测量表明OH-大量耗尽或几乎不存在，尽管其被假定为羟基磷灰石晶格的成分。测定骨晶体OH含量的分析方法依赖于可能使结果产生偏差的程序或假设，例如化学预处理以消除有机基质的干扰。我们展示了一种二维固态核磁共振（NMR）光谱技术，该技术检测骨晶体的质子光谱，同时抑制干扰基质信号，消除了除低温研磨以外的标本预处理的需要。几种哺乳动物的新鲜冷冻和研磨全骨的结果表明，骨晶体OH-是很容易检测到的，粗略估计产生的OH-含量的人皮质骨的约20%的量预期在化学计量的羟基磷灰石。这一发现揭示了正常和异常骨矿物质代谢的生化过程。
Previous measurements of the hydroxyl (OH-) ion content of the calcium phosphate crystals of bone mineral have indicated a substantial depletion or near-absence of OH-, despite its presumed status as a constituent of the hydroxyapatite lattice. Analytical methods for determining bone crystal OH content have depended on procedures or assumptions that may have biased the results, such as chemical pretreatment to eliminate interference from the organic matrix. We demonstrate a two-dimensional solid-state nuclear magnetic resonance (NMR) spectroscopy technique that detects the proton spectrum of bone crystals while suppressing the interfering matrix signals, eliminating the need for specimen pretreatment other than cryogenic grinding. Results on fresh-frozen and ground whole bone of several mammalian species show that the bone crystal OH- is readily detectable; a rough estimate yields an OH- content of human cortical bone of about 20% of the amount expected in stoichiometric hydroxyapatite. This finding sheds light on the biochemical processes underlying normal and abnormal bone mineral metabolism.