Complementary DNA Cloning and Characterization of Pearlin, a New Class of Matrix Protein in the Nacreous Layer of Oyster Pearls
Complementary DNA Cloning and Characterization of Pearlin, a New Class of Matrix Protein in the Nacreous Layer of Oyster Pearls
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DOI：
10.1007/pl00021687
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发表时间：
2000-09
影响因子：
3
通讯作者：
Tomoyuki Miyashita;R. Takagi;M. Okushima;S. Nakano;Hiroshi Miyamoto;E. Nishikawa;Aizo Matsushiro
中科院分区：
文献类型：
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作者：
Tomoyuki Miyashita;R. Takagi;M. Okushima;S. Nakano;Hiroshi Miyamoto;E. Nishikawa;Aizo Matsushiro
钙化壳层由CaCO3、文石或方解石的两种多晶型物和有机基质组成。有机基质由 EDTA 可溶部分和不溶部分组成。这些分数被认为可以调节复杂壳结构的形成。用 0.3 M EDTA 对珍珠粉进行脱钙后，用 0.3 M EDTA/8 M 尿素提取 EDTA 不溶部分。这一提取步骤使我们能够几乎均匀地纯化一类新型 EDTA 不溶性蛋白质 Pearlin。 Pearlin 的分子量约为 15 kDa，含有硫酸化粘多糖。我们克隆了 Pearlin 的互补 DNA 编码并推导了其完整的氨基酸序列。序列分析显示Pearlin由129个氨基酸组成，其中Gly（10.8%）、Tyr（10.0%）、Cys（8.5%）、Asn（7.7%）、Asp（7.7%）和Arg（7.7%）比例较高。 Northern印迹分析表明Pearlin信使RNA在外套膜上皮中特异性表达。从测序数据来看，Pearlin与富含Ala和Gly的纤维蛋白有很大不同。讨论了该蛋白质在生物矿化中的功能。
Calcified shell layer is composed of two polymorphs of CaCO3, aragonite or calcite, and an organic matrix. The organic matrix consists of EDTA-soluble and insoluble fractions. These fractions are thought to regulate the formation of the elaborate shell structure. After decalcification of powdered pearl with 0.3 M EDTA, an EDTA-insoluble fraction was extracted with 0.3 M EDTA/8 M urea. This extraction step enabled us to purify a new class of EDTA-insoluble protein, Pearlin, almost homogeneously. Pearlin has a molecular weight of about 15 kDa and contains a sulfated mucopolysaccharide. We cloned the complementary DNA coding for Pearlin and deduced its complete amino acid sequence. Sequence analysis reveals that Pearlin is composed of 129 amino acids with a high proportion of Gly (10.8%), Tyr (10.0%), Cys (8.5%), Asn (7.7%), Asp (7.7%), and Arg (7.7%). Northern blot analysis showed that Pearlin messenger RNA was expressed specifically in mantle epithelium. From the sequencing data, Pearlin was shown to be quite different from the fibrous protein rich in Ala and Gly. The function of this protein in biomineralization is discussed.