自然丰富的43Ca固态核磁共振光谱的骨
Jiadi Xu1, Peizhi Zhu, Zhehong Gan
1Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, USA.
Journal of the American Chemical Society
|August 5, 2010
概括
这项研究证明了天然丰富的43Ca神奇角度旋转的骨NMR,与骨矿物质模型相比,揭示了不同的环境. 这些发现提升了对的理解.
科学领域:
- 固态NMR光谱学 固态NMR光谱学
- 骨生物矿物化的生物矿物化
- 的协调化学化学
背景情况:
- 了解在骨健康中的作用需要详细的结构信息.
- 之前对骨结构的研究面临着高分辨率的挑战.
- 模型化合物的固态NMR推进了骨矿物质研究,但43Ca NMR的应用受到了低灵敏度和自然丰富性的限制.
研究的目的:
- 为了证明自然丰富的43Ca神奇角度旋转 (MAS) 在骨头上的NMR实验.
- 描述皮层骨中的协调环境.
- 为了比较骨环境与模型化合物,如酸和碳酸酸.
主要方法:
- 在牛皮层骨粉末上进行了自然丰富的43Ca MAS NMR实验.
- 通过将43Ca NMR光谱与氧酸盐和碳酸酸盐进行比较.
- 利用拉曼光谱来获得补充的结构洞察力.
- 在碳酸阿帕和骨素的混合物上进行2D三次量子43Ca MAS NMR.
主要成果:
- 皮层骨的43Ca NMR光谱与酸和碳酸酸有显著差异.
- 拉曼光谱表明,骨环境更类似于碳酸酸盐.
- 皮层骨表现出比模型化合物更大的四极合常数.
- 碳酸盐度增加与43Ca化学转移频率降低相关.
- 2D核磁共振揭示了骨蛋白混合物中的蛋白质结合和自由位.
结论:
- 自然丰富的43Ca MAS NMR对于研究骨结构是可行的.
- 骨的协调环境不同于纯酸和碳酸.
- 这项研究提供了有关骨结合的见解,以及它与骨素等蛋白质的相互作用.
相关概念视频
01:10Carbon-13 (¹³C) NMR: Overview
Carbon-13 is a naturally occurring NMR-active isotope of carbon with a low natural abundance of 1.1%. In contrast, carbon-12 is the most abundant isotope of carbon with zero nuclear spin. Therefore, it is NMR inactive. The gyromagnetic ratio of carbon-13 is smaller than that of protons. As a result, carbon-13 resonance is about 6000 times weaker than proton resonance. For a given magnetic field strength, the resonance frequency of carbon-13 is about one-fourth of the resonance frequency for...
01:20NMR Spectrometers: Overview
NMR spectrometers consist of a strong magnet, a radiofrequency transmitter, and a detector attached to a computer console for recording spectra of samples containing NMR-active nuclei. In first-generation NMR instruments called continuous-wave spectrometers, the resonance frequencies of the nuclei are determined by frequency-sweep or field-sweep methods. The magnetic field strength is fixed and the rf signal is swept in the former, while the radiofrequency signal is fixed and the magnetic field...
01:10X-ray Diffraction of Biological Samples
X-ray diffraction or XRD is an analytical tool that utilizes X-rays to study ordered structures such as crystalline organic and inorganic samples, polycrystalline materials, proteins, carbohydrates, and drugs.
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
01:18The Bone Matrix
Bone contains a relatively small number of cells entrenched in a matrix of collagen fibers that provide an adherent surface for inorganic salt crystals. Both components of the matrix, organic and inorganic, contribute to the unusual properties of bone. Without collagen, bones would be brittle and shatter easily. Without mineral crystals, bones would flex and provide little support. This can be observed by an experiment: when the minerals of a bone are dissolved by soaking the bone in acid or...
01:27Compact Bone
Most bones contain compact and spongy osseous tissue, but their distribution and concentration vary based on the bone's overall function.
Compact bone, also called cortical bone, is the denser, stronger of the two types of bone tissue. It is found under the periosteum and in the diaphyses of long bones, where it provides support and protection. The microscopic structural unit of compact bone is called an osteon, or haversian system. Each osteon is composed of concentric rings of calcified...
Compact bone, also called cortical bone, is the denser, stronger of the two types of bone tissue. It is found under the periosteum and in the diaphyses of long bones, where it provides support and protection. The microscopic structural unit of compact bone is called an osteon, or haversian system. Each osteon is composed of concentric rings of calcified...
01:15NMR Spectroscopy: Chemical Shift Overview
The position of the absorption signal of a sample is reported relative to the position of the signal of tetramethylsilane (TMS), which is added as an internal reference while recording spectra. The difference between the absorption frequencies of the sample and TMS (in Hz) is divided by the spectrometer operating frequency (in MHz) to obtain a dimensionless quantity called the chemical shift. It is reported on the δ (delta) scale and expressed in parts per million.
For instance, the proton...
For instance, the proton...