CHARACTERIZATION OF A CYSTINE-RICH POLYPHENOLIC PROTEIN FAMILY FROM THE BLUE MUSSEL MYTILUS-EDULIS-L
CHARACTERIZATION OF A CYSTINE-RICH POLYPHENOLIC PROTEIN FAMILY FROM THE BLUE MUSSEL MYTILUS-EDULIS-L
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DOI：
10.2307/1542413
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发表时间：
1992-08-01
影响因子：
1.6
通讯作者：
WAITE, JH
中科院分区：
文献类型：
--
作者：
RZEPECKI, LM;HANSEN, KM;WAITE, JH
海洋双壳类软体动物在足的酚腺和附腺中合成蛋白质，所述蛋白质将水解后羟基化的氨基酸3，4-二羟基苯丙氨酸（DOPA）整合到它们的一级序列中。这些多酚类蛋白质作为深海丝的结构和粘附成分，形成了器官外的固着器。一个家族的深海前体，以前的特点是在一些mytiloid物种，由蛋白质70-130 kDa之间含有8-18摩尔%的多巴。从蓝贻贝（Mytilus edulis Linnaeus，1758）的脚分离的高分子量前体在此被命名为Mefp-1。我们现在提出证据的发生，在M。edulis，属于第二个结构上不相关的DOPA蛋白家族（Mefp-2），分子量约为42-47 kDa。这些新的蛋白质含有2-3摩尔%的多巴，并且与Mefp-1形成惊人的对比，还富含含二硫化物的氨基酸胱氨酸（6-7摩尔%）。考虑到Mefp-1和2的氨基酸组成和深海丝的末端粘着斑表明，Mefp-2占斑蛋白的约25%，而Mefp-1含量约为5%。Mefp-2家族表现出电泳微异质性，但成员共享相似的N-和C-末端氨基酸序列。胰蛋白酶水解后分离的肽的分析表明，Mefp-2的一级序列是串联重复的，具有至少三种类型的基序。基序的序列简并性大于Mefp-1。Mefp-2与已知的结构蛋白具有最小的序列同源性，并且可能是斑块基质的结构元件。
Marine bivalve mollusks synthesize, in the phenol and accessory glands of the foot, proteins that integrate the post-translationally hydroxylated amino acid 3,4-dihydroxyphenylalanine (DOPA) into their primary sequence. These polyphenolic proteins serve as structural and adhesive components of the byssal threads which form the extraorganismic holdfast. One family of byssal precursors, previously characterized in a number of mytiloid species, consists of proteins between 70-130 kDa containing 8-18 mol % DOPA. The high molecular weight precursor isolated from the foot of the blue mussel (Mytilus edulis Linnaeus, 1758) is here designated as Mefp-1. We now present evidence for the occurrence, in M. edulis, of a second, structurally unrelated, family of DOPA proteins (Mefp-2) of about 42-47 kDa. These novel proteins contain 2-3 mol % DOPA and, in startling contrast to Mefp-1, are also enriched in the disulphide-containing amino acid cystine (6-7 mol %). Consideration of the amino acid compositions of Mefp-1 and 2 and of the terminal adhesive plaques of byssal threads suggests that Mefp-2 makes up about 25% of plaque protein, whereas Mefp-1 content is about 5%. The Mefp-2 family exhibits electrophoretic microheterogeneity, but members share similar N- and C-terminal amino acid sequences. Analysis of peptides isolated after tryptic hydrolysis suggests that the primary sequence of Mefp-2 is tandemly repetitive, with at least three types of motif The sequence degeneracy of the motifs is greater than in Mefp-1. Mefp-2 has minimal sequence homology with known structural proteins and may be a structural element of the plaque matrix.