Effect of Otoconial Proteins Fetuin A, Osteopontin, and Otoconin 90 on the Nucleation and Growth of Calcite.
Effect of Otoconial Proteins Fetuin A, Osteopontin, and Otoconin 90 on the Nucleation and Growth of Calcite.
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DOI：
10.1021/cg501001r
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发表时间：
2015-01-07
影响因子：
3.8
通讯作者：
De Yoreo, James J.
中科院分区：
文献类型：
--
作者：
Hong, Mina;Moreland, K. Trent;Chen, Jiajun;Teng, Henry H.;Thalmann, Ruediger;De Yoreo, James J.
我们研究了三种与耳石形成相关的蛋白质的作用，包括胎球蛋白A、骨桥蛋白（OPN）和耳石蛋白90（OC 90）。原位原子力显微镜（AFM）研究这些蛋白质对方解石表面原子台阶生长的影响，以了解它们对生长动力学的影响。我们还使用扫描电子显微镜检查这些蛋白质对晶体形态的影响。发现所有三种蛋白质都是方解石生长的有效抑制剂，尽管胎球蛋白A在低于约40 nM的浓度下促进生长，并且仅在较高浓度下成为抑制剂。然后，我们使用原位光学显微镜观察这些蛋白质吸附到云母表面上的薄膜上的方解石成核。通过测量作为过饱和度的函数的方解石成核速率，确定了每种蛋白质的控制非均质成核的自由能垒的界面能的值。OPN和OC 90膜导致显着降低的界面能相比，在本体溶液中的均匀方解石成核的值。在实验误差范围内，胎球蛋白A的值与原液的值相等。Zeta电位测量显示所有蛋白质都具有负表面电荷，并且根据胎球蛋白A > OC 90> OPN的顺序在大小上变化。此外，界面能表现出与zeta电位成反比。在类似于以前的测量多糖膜，这种缩放表明蛋白质之间的差异产生的蛋白质表面电荷的溶液-基板的界面能的影响。我们研究了三种耳石蛋白对方解石生长动力学的影响，通过原位原子力显微镜和晶体形态的扫描电子显微镜。我们使用原位光学显微镜，以确定的自由能垒和界面能控制方解石成核膜的蛋白质。通过将表面电荷与每种蛋白质的溶液-底物界面能相关联的zeta电位测量，使结果合理化。
We investigated the roles of three proteins associated with the formation of otoconia including fetuin A, osteopontin (OPN), and otoconin 90 (OC90). In situ atomic force microscopy (AFM) studies of the effects of these proteins on the growth of atomic steps on calcite surfaces were performed to obtain insight into their effects on the growth kinetics. We also used scanning electron microscopy to examine the effects of these proteins on crystal morphology. All three proteins were found to be potent inhibitors of calcite growth, although fetuin A promoted growth at concentrations below about 40 nM and only became an inhibitor at higher concentrations. We then used in situ optical microscopy to observe calcite nucleation on films of these proteins adsorbed onto mica surfaces. By measuring the calcite nucleation rate as a function of supersaturation, the value of the interfacial energy that controls the free energy barrier to heterogeneous nucleation was determined for each protein. OPN and OC90 films led to significantly reduced interfacial energies as compared to the value for homogeneous calcite nucleation in bulk solution. The value for fetuin A was equal to that for bulk solution within experimental error. Zeta potential measurements showed all of the proteins possessed negative surface charge and varied in magnitude according to sequence fetuin A > OC90 > OPN. In addition, the interfacial energies exhibited an inverse scaling with the zeta potential. In analogy to previous measurements on polysaccharide films, this scaling indicates the differences between the proteins arise from the effect of protein surface charge on the solution–substrate interfacial energy. We investigated effects of three otoconial proteins on calcite growth kinetics by in situ atomic force microscopy and on crystal morphology by scanning electron microscopy. We used in situ optical microscopy to determine the free energy barriers and interfacial energies controlling calcite nucleation on films of the proteins. The results were rationalized through zeta potential measurements relating surface charge to solution−substrate interfacial energy for each protein.
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影响因子：
56.9
作者：
Davis, KJ;Dove, PM;De Yoreo, JJ
通讯作者：
De Yoreo, JJ
影响因子：
1.4
作者：
ANNIKO, M;YLIKOSKI, J;WROBLEWSKI, R
通讯作者：
WROBLEWSKI, R
影响因子：
1.9
作者：
Land, TA;DeYoreo, JJ;Lee, JD
通讯作者：
Lee, JD
DOI：
10.1073/pnas.1222162110
发表时间：
2013-06-04
影响因子：
11.1
作者：
Giuffre, Anthony J.;Hamm, Laura M.;Dove, Patricia M.
通讯作者：
Dove, Patricia M.
影响因子：
3
作者：
Lins, U;Farina, M;Kachar, B
通讯作者：
Kachar, B