Recent advances in amelogenin biochemistry
Recent advances in amelogenin biochemistry
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DOI：
10.3109/03008209509013713
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发表时间：
1995-01-01
影响因子：
2.9
通讯作者：
MoradianOldak, J
中科院分区：
文献类型：
--
作者：
Fincham, AG;MoradianOldak, J
本文综述了釉原蛋白生物化学在三个方面的研究进展：（i）釉原蛋白的表达;（ii）釉原蛋白的翻译后和分泌后加工;（iii）釉原蛋白的结构和功能。最近对釉原蛋白表达的研究（1，2）表明，小鼠釉原蛋白RNA的选择性剪接产生7种不同的mRNA，编码长度为194至44个氨基酸残基的釉原蛋白蛋白。一个多克隆抗体的序列的194个残基的鼠釉原蛋白在体内确定了这种蛋白质。虽然有几项研究报道，釉原蛋白是后磷酸化，它已被证明很难证实这一观点？牛和猪TRAP和LRAP釉原蛋白的质谱研究已经确定了在位置-16处的磷酸丝氨酸残基，如最初由Takagi等报道的。(3)有180个残基的牛釉原蛋白此外，我们发现羧基末端釉原蛋白蛋白水解加工的详细机制似乎与以前报道的不同。(4)就釉原蛋白结构而言，众所周知，釉原蛋白形成聚集结构。采用重组釉原蛋白和动态光散射仪器的研究表明，聚集体结构半径为15-20纳米，对应于2-3百万道尔顿的质量。通过透射电子显微镜和原子力显微镜对这些聚集体进行成像表明，这些结构相当于发育中釉质的电子显微镜照片中所见的“斑点状"或”颗粒状"物质。总之，釉原蛋白生物化学的这些进展导致了釉原蛋白的结构，加工和功能在釉质生物矿化的新观点。
This paper reviews advances in amelogenin biochemistry in three areas; (i) amelogenin expression; (ii) amelogenin posttranslational and post-secretory processing, and (iii) amelogenin structure and function. Recent studies of amelogenin expression(1,2) have demonstrated that alternative-splicing of mouse amelogenin RNA generates seven distinct mRNAs, coding for amelogenin proteins from 194 to 44 amino acid residues in length. A polyclonal antibody to a sequence of the 194-residue murine amelogenin identified this protein in vivo. While several studies have reported that amelogenins are post translationally phosphorylated, it has proved difficult to confirm this view-h?ass spectrometry studies of bovine and porcine TRAP and LRAP amelogenins have established a phosphoserine residue at position-16 as originally reported by Takagi et al.(3) for a 180-residue bovine amelogenin. Also, we discovered that the detailed mechanism(s) of carboxy terminal amelogenin proteolytic processing appear different than previously reported.(4) In terms of amelogenin structure, it is well known that amelogenins form aggregated structures. Studies employing a recombinant amelogenin and dynamic light-scattering instrumentation demonstrated aggregate structures of 15-20 nm in radius, corresponding to a mass of 2-3 million daltons. Imaging these aggregates by transmission electron and atomic force microscopy Suggested that these structures are equivalent to the ''stippled'' or ''granular'' material seen in electron photomicrographs of developing enamel. Collectively, these advances in amelogenin biochemistry lead to a new view of amelogenin structure, processing and functions in enamel biomineralization.