Molecular mechanism of the nacreous layer formation in Pinctada maxima
Molecular mechanism of the nacreous layer formation in Pinctada maxima
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DOI：
10.1006/bbrc.2000.2274
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发表时间：
2000-03-05
影响因子：
3.1
通讯作者：
Samata, T
中科院分区：
文献类型：
--
作者：
Kono, M;Hayashi, N;Samata, T
我们克隆了在珠母层编码两种软体动物壳基质蛋白N66和N14的cdna。N66由碳酸酐酶样结构域和重复结构域组成，如P. fucata珍珠中的珍珠素(1)所述。N14与N16是同源的，N16最近在P. fucata的珠层中被发现(2)，其特征是高比例的Gly， Tyr和Asn以及NG重复序列。这些蛋白的分子量估计分别为59,814和13,734 Da。同源蛋白（NBB/nacrein和N14/N16）的序列比对和重复序列长度显示出明显的结构差异。N66和N14的重复序列较长，这可能是最大藻具有良好钙化特性的原因。体外结晶实验表明，N66和N14的混合物一旦吸附在不溶性基质的膜上，就可以诱导出与珠光层高度相似的板状文石层。(C) 2000年学术出版社。
We have cloned the cDNAs that encode two kinds of molluscan shell matrix proteins, namely N66 and N14, in the nacreous layer of Pinctada maxima. N66 is composed of carbonic anhydrase-like and repeat domains, as described for nacrein (1) in the pearls of P. fucata. N14 is homologous to N16, recently found in the nacreous layer of P. fucata (2) and is characterized by high proportions of Gly, Tyr, and Asn together with NG repeat sequences. The molecular weights of these proteins were estimated as 59,814 and 13,734 Da, respectively. Structural differences were clearly indicated in the alignment and length of the repeat sequences of the sets of the homogeneous proteins (NBB/nacrein and N14/N16). The longer repeat sequences of N66 and N14 may be responsible for P. maxima's excellent property of calcification. The in vitro crystallization experiments revealed that the mixture of N66 and N14 could induce platy aragonite layers highly similar to the nacreous layer, once adsorbed onto the membrane of the water-insoluble matrix. (C) 2000 Academic Press.