Membrane permeabilizing activity of pathogenesis-related protein linusitin from flax seed
Membrane permeabilizing activity of pathogenesis-related protein linusitin from flax seed
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DOI：
10.1094/mpmi.1998.11.7.610
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发表时间：
1998-07-01
影响因子：
3.5
通讯作者：
Menestrina, G
中科院分区：
文献类型：
--
作者：
Anzlovar, S;Dalla Serra, M;Menestrina, G
Linusitin是从亚麻种子中分离的25-kDa的第5类病程相关（PR）蛋白。已经提出PR-5蛋白通过透化真菌膜来发挥其抗真菌活性。使用荧光方法，已被用于抗菌蛋白质以外的PR蛋白，我们测试了这一假设。该方法基于染料钙黄绿素从小或大单层脂质囊泡内部的释放。作为蛋白质和脂质浓度和膜组成的函数的蛋白质诱导的钙黄绿素释放的量进行了研究。所有的结果都可以用一个可用的统计模型来解释，该模型预测钙黄绿素从囊泡中释放是四聚体蛋白聚集的结果。这种聚集体是否对应于一个跨膜孔或另一个蛋白质复合物，扰乱膜仍有待建立。囊泡的脂质组成影响了linusitin的透化活性。通过增加囊泡中带负电荷的磷脂的含量、将甾醇类纳入膜中或降低溶液的pH值来观察活性的增加。在实际的植物-真菌相互作用中所观察到的透化活性变化的可能作用进行了讨论。
Linusitin is a 25-kDa pathogenesis-related (PR) protein of class 5 isolated from flax seeds. It has been proposed that PR-5 proteins exert their antifungal activity by permeabilizing fungal membranes. Using a fluorescent method that has been used for antimicrobial proteins other than PR proteins, we tested this hypothesis. The method is based on the release of the dye calcein from the inside of either small or large unilamellar lipid vesicles. The amount of calcein release induced by the protein was studied as a function of protein and lipid concentration and of membrane composition. All the results could be accounted for with an available statistical model, The model predicts that calcein release from the vesicles is a result of the tetrameric protein aggregation. Whether this aggregate corresponds to a transmembrane pore or to another protein complex that perturbs the membrane remains to be established. The lipid composition of the vesicles affected the permeabilization activity of linusitin. An increase of activity was observed by increasing the content of negatively charged phospholipids in the vesicles, inclusion of sterols into the membrane, or decreasing the pH of the solution. The possible roles of the observed changes in permeabilizing activity in actual plant-fungus interactions are discussed.