The proteolytic processing of amelogenin by enamel matrix metalloproteinase (MMP-20) is controlled by mineral ions.
The proteolytic processing of amelogenin by enamel matrix metalloproteinase (MMP-20) is controlled by mineral ions.
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搪瓷基质金属蛋白酶（MMP-20）对氨基蛋白蛋白的蛋白水解加工受矿物离子的控制。
DOI：
10.1016/j.bbagen.2012.11.021
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发表时间：
2013-03
影响因子：
3
通讯作者：
Habelitz, Stefan
中科院分区：
文献类型：
--
作者：
Khan, Feroz;Liu, Haichuan;Reyes, Aileen;Witkowska, H. Ewa;Martinez-Avila, Olga;Zhu, Li;Li, Wu;Habelitz, Stefan
牙釉质合成是磷灰石矿化过程中基质分泌、组装和加工同时进行的高度动态过程。MMP-20是第一个水解淀粉原蛋白的蛋白酶，产生特定的裂解产物，在特定的矿物组成和ph下自组装成纳米结构。本研究阐明了MMP-20蛋白在不同矿物组成下水解重组全长人淀粉原蛋白（rH174）的酶动力学。利用MMP-20在不同理化条件下对重组淀粉原蛋白进行了裂解，并利用SDS-PAGE和MALDI-TOF ms对产物进行了分析。结果表明，矿物离子对rH174的裂解模式和酶动力学有较大影响。在所选的5种矿物离子组成中，MMP-20在高钙浓度下效率最高，而在高磷酸盐浓度下效率最低，在高钙和高磷酸盐浓度下效率最低。在大多数成分中，N端和c端在几个地方被快速切割，但在高钙和高磷酸盐含量的溶液中，淀粉原蛋白的中心区域受到一定程度的保护。这些体外研究表明，蛋白质溶液的化学性质可以显著改变MMP-20对淀粉原蛋白的加工，这可能对体内基质组装和随后的磷酸钙矿化产生重大影响。本研究阐述了在牙釉质发育过程中有机基质转化为矿化组织的可能性。
Enamel synthesis is a highly dynamic process characterized by simultaneity of matrix secretion, assembly and processing during apatite mineralization. MMP-20 is the first protease to hydrolyze amelogenin, resulting in specific cleavage products that self-assemble into nanostructures at specific mineral compositions and pH. In this investigation, enzyme kinetics of MMP-20 proteolysis of recombinant full-length human amelogenin (rH174) under different mineral compositions is elucidated. Recombinant amelogenin was cleaved by MMP-20 under various physicochemical conditions and the products were analyzed by SDS-PAGE and MALDI-TOF MS. It was observed that mineral ions largely affect cleavage pattern, and enzyme kinetics of rH174 hydrolysis. Out of the five selected mineral ion compositions, MMP-20 was most efficient at high calcium concentration, whereas it was slowest at high phosphate, and at high calcium and phosphate concentrations. In most of the compositions, N- and C-termini were cleaved rapidly at several places but the central region of amelogenin was protected up to some extent in solutions with high calcium and phosphate contents. These in vitro studies showed that the chemistry of the protein solutions can significantly alter the processing of amelogenin by MMP-20, which may have significant effects in vivo matrix assembly and subsequent calcium phosphate mineralization. This study elaborates the possibilities of the processing of the organic matrix into mineralized tissue during enamel development.
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影响因子：
3
作者：
He, Xiaodong;Li, Wu;Habelitz, Stefan
通讯作者：
Habelitz, Stefan
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：
4.2
作者：
AOBA, T;FUKAE, M;MORENO, EC
通讯作者：
MORENO, EC
影响因子：
2.9
作者：
Llano, E;Pendas, AM;LopezOtin, C
通讯作者：
LopezOtin, C
影响因子：
7.6
作者：
Ozdemir, D;Hart, PS;Hart, TC
通讯作者：
Hart, TC