Atomic force microscopy images suggest aggregation mechanism in cerato-platanin
Atomic force microscopy images suggest aggregation mechanism in cerato-platanin
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DOI：
10.1007/s00249-007-0159-x
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发表时间：
2007-09-01
影响因子：
2
通讯作者：
Tiribilli, B.
中科院分区：
文献类型：
--
作者：
Sbrana, F.;Bongini, L.;Tiribilli, B.
角藻-铂蛋白（CP）是“角藻-铂蛋白家族”的第一个成员，是一种由毛状角藻产生的中度疏水蛋白，而毛状角藻是一种严重的植物疾病“溃疡斑”的致病因子。该蛋白定位于真菌的细胞壁，似乎参与了宿主与平面的相互作用，并诱导细胞坏死和植物抗菌素合成（最早的植物防御相关事件之一）。近年来，已确定CP与其他真菌表面蛋白一样，在体外具有自组装能力。本文利用原子力显微镜（AFM）图像对CP的聚集体进行了表征。我们观察到CP倾向于形成早期环状低聚物，这些低聚物似乎构成了分层聚集过程的基本砖块，最终导致大的大纤维聚集。一个简单的模型，假设当暴露的表面减少时，聚集在能量上是有利的，与测量的聚集的形状和大小是相容的。所提出的模型有助于理解CP和许多其他真菌表面蛋白发挥作用的机制。
Cerato-platanin (CP), the first member of the "cerato-platanin family", is a moderately hydrophobic protein produced by Ceratocystis fimbriata, the causal agent of a severe plant disease called "canker stain". The protein is localized in the cell wall of the fungus and it seems to be involved in the host-plane interaction and induces both cell necrosis and phytoalexin synthesis (one of the first plant defence-related events). Recently, it has been determined that CP, like other fungal surface protein, is able to self assemble in vitro. In this paper we characterize the aggregates of CP by Atomic Force Microscopy (AFM) images. We observe that CP tends to form early annular-shaped oligomers that seem to constitute the fundamental bricks of a hierarchical aggregation process, eventually resulting in large macrofibrillar assemblies. A simple model, based on the hypothesis that the aggregation is energetically favourable when the exposed surface is reduced, is compatible with the measured aggregates' shape and size. The proposed model can help to understand the mechanism by which CP and many other fungal surface proteins exert their effects.