Linking adhesive and structural proteins in the attachment plaque of Mytilus californianus
Linking adhesive and structural proteins in the attachment plaque of Mytilus californianus
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DOI：
10.1074/jbc.m604357200
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发表时间：
2006-09-08
影响因子：
4.8
通讯作者：
Waite, J. Herbert
中科院分区：
文献类型：
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作者：
Zhao, Hua;Waite, J. Herbert
加州贻贝的深海附着在潮湿的环境中提供了安全的附着力，这是大多数合成聚合物仍然无法实现的壮举。基质辅助激光解吸电离质谱用于探测玻璃盖片上的粘附蛋白质的深渊附着斑块的足迹。除了丰富的mcfp-3蛋白家族（Zhao，H.，Robertson，N. B.，Jewhurst，S.一、和Waite，J.H.（2006）J.Biol.Chem.281，11090 - 11096），在足迹中鉴定了两种新的蛋白质，mcfp-5和mcfp-6，其质量分别为8.9kDa和11.6kDa，部分表征并从cDNA文库中完全测序。mcfp-5在其碱性pI和丰富的3，4-二羟基苯基-L-丙氨酸（多巴; 30mol%）方面类似于mcfp-3，但在两个方面不同：它在一级序列上更均一并且是多磷酸化的。mcfp-6是碱性的并且含有少量的多巴（< 5摩尔%）。与mcfp-3和-5相反，酪氨酸占20摩尔%，半胱氨酸占11摩尔%，其中三分之一保持硫醇化。考虑到多巴和半胱氨酸在pH 8.2（海水）下的氧化不稳定性，我们测试了硫醇通过加合物形成来抑制多巴醌的假设。斑块足迹水解和筛选半胱氨酸多巴醌加合物使用苯硼酸亲和色谱。检测到5-S-半胱氨酰多巴接近1 mol %。结果表明，mcfp-6可以提供一个表面耦合多巴丰富的蛋白质和斑块蛋白质的大部分之间的内聚连接。
The byssal attachment of California mussels Mytilus californianus provides secure adhesion in the presence of moisture, a feat that still eludes most synthetic polymers. Matrix-assisted laser desorption ionization mass spectrometry was used to probe the footprints of byssal attachment plaques on glass cover slips for adhesive proteins. Besides the abundant mcfp-3 protein family (Zhao, H., Robertson, N. B., Jewhurst, S. A., and Waite, J. H. (2006) J. Biol. Chem. 281, 11090 - 11096), two new proteins, mcfp-5 and mcfp-6, with masses of 8.9 kDa and 11.6 kDa, respectively, were identified in footprints, partially characterized and completely sequenced from a cDNA library. mcfp-5 resembles mcfp-3 in its basic pI and abundant 3,4-dihydroxyphenyl-L-alanine (Dopa; 30 mol %), but is distinct in two respects: it is more homogeneous in primary sequence and is polyphosphorylated. mcfp-6 is basic and contains a small amount of Dopa (< 5 mol %). In contrast to mcfp-3 and - 5, tyrosine prevails at 20 mol %, and cysteine is present at 11 mol %, one-third of which remains thiolate. Given the oxidative instability of Dopa and cysteine at pH 8.2 (seawater), we tested the hypothesis that thiols serve to scavenge dopaquinones by adduct formation. Plaque footprints were hydrolyzed and screened for cysteine dopaquinone adducts using phenylboronate affinity chromatography. 5-S-Cysteinyldopa was detected at nearly 1 mol %. The results suggest that mcfp-6 may provide a cohesive link between the surface-coupling Dopa-rich proteins and the bulk of the plaque proteins.