Effect of phosphorylation on the interaction of calcium with leucine-rich amelogenin peptide.
Effect of phosphorylation on the interaction of calcium with leucine-rich amelogenin peptide.
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DOI：
10.1111/j.1600-0722.2011.00900.x
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发表时间：
2011-12
影响因子：
1.9
通讯作者：
Margolis HC
中科院分区：
文献类型：
--
作者：
Le Norcy E;Kwak SY;Allaire M;Fratzl P;Yamakoshi Y;Simmer JP;Margolis HC
釉原蛋白进行自组装，并在引导釉质矿物形成中发挥重要作用。富含亮氨酸的釉原蛋白多肽(LRAP)是釉原蛋白基因的选择性剪接产物，由全长釉原蛋白的N端(含唯一的磷酸基团)和C端组成。本研究旨在利用小角X射线散射(SAXS)进一步研究有无钙离子对LRAP自组装过程中磷酸化作用的影响。与我们先前对磷酸化(+P)和非磷酸化(−P)LRAP的动态光散射结果一致，小角X射线光谱分析显示，在pH 7.4时，LRAP(−P)的回转半径(Rg)(46.3-48.0)大于LRAP(+P)的回转半径(Rg)(25.0-27.4)。然而，添加钙(直到2.5mM)导致LRAP(+P)的Rg显著增加(最高可达46.4ä)，而对LRAP(−P)的颗粒大小影响相对较小。此外，小角X射线光谱分析表明，在有钙和无钙的情况下，LRAP(−P)具有致密的折叠结构，而随着钙的加入，LRAP(+P)的构象从未折叠的结构转变为更紧密的结构。我们的结论是，LRAP(+P)中的单一磷酸基团引起了重要的功能构象变化，提示在釉质形成的早期阶段，磷酸化也可能影响釉原蛋白的构象和蛋白质-矿物相互作用。
Amelogenin undergoes self-assembly and plays an essential role in guiding enamel mineral formation. The Leucine-Rich Amelogenin Peptide (LRAP) is an alternative splice product of the amelogenin gene composed of the N-terminus (containing the only phosphate group) and C-terminus of full-length amelogenin. This study was conducted to further investigate the role of phosphorylation in LRAP self-assembly in the presence and absence of calcium using Small Angle X-ray Scattering (SAXS). Consistent with our prior dynamic light scattering findings for phosphorylated (+P) and non-phosphorylated (−P) LRAP, SAXS analyses revealed radii of gyration (Rg) for LRAP(−P) (46.3 – 48.0 Å) that were larger than those for LRAP(+P) (25.0 – 27.4 Å) at pH 7.4. However, added calcium (up to 2.5 mM) induced significant increases in the Rg of LRAP(+P) (up to 46.4 Å), while it had relatively little effect on LRAP(−P) particle size. Furthermore, SAXS analyses suggested compact folded structures for LRAP(−P) in the presence and absence of calcium, whereas LRAP(+P) conformation changed from an unfolded structure to a more compact structure upon calcium addition. We conclude that the single phosphate group in LRAP(+P) induces functionally important conformational changes, suggesting that phosphorylation may also influence amelogenin conformation and protein-mineral interactions during early stages of amelogenesis.
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影响因子：
3
作者：
Beniash, Elia;Metzler, Rebecca A.;Lam, Raymond S. K.;Gilbert, P. U. P. A.
通讯作者：
Gilbert, P. U. P. A.
影响因子：
2.9
作者：
Buchko, Garry W.;Tarasevich, Barbara J.;Bekhazi, Jacky;Snead, Malcolm L.;Shaw, Wendy J.
通讯作者：
Shaw, Wendy J.
影响因子：
2.5
作者：
Allaire, Marc;Yang, Lin
通讯作者：
Yang, Lin
影响因子：
6.1
作者：
Konarev, PV;Volkov, VV;Svergun, DI
通讯作者：
Svergun, DI
影响因子：
6.2
作者：
Aichmayer, Barbara;Wiedemann-Bidlack, Felicitas B.;Gilow, Christoph;Simmer, James P.;Yamakoshi, Yasuo;Emmerling, Franziska;Margolis, Henry C.;Fratzl, Peter
通讯作者：
Fratzl, Peter