HAMLET interacts with lipid membranes and perturbs their structure and integrity.
HAMLET interacts with lipid membranes and perturbs their structure and integrity.
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DOI：
10.1371/journal.pone.0009384
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发表时间：
2010-02-23
期刊：
影响因子：
3.7
通讯作者：
Karlsson R
中科院分区：
文献类型：
--
作者：
Mossberg AK;Puchades M;Halskau Ø;Baumann A;Lanekoff I;Chao Y;Martinez A;Svanborg C;Karlsson R
细胞膜相互作用依赖于脂质双层成分和插入膜内的分子，包括特异性受体。哈姆雷特（对肿瘤细胞具有致死性的人α-乳白蛋白）是部分未折叠的α-乳白蛋白（HLA）和油酸的杀肿瘤复合物，其被肿瘤细胞内化，表明与磷脂双层和/或特异性受体的相互作用可能是杀肿瘤作用所必需的。这项研究检查了哈姆雷特是否与人工膜相互作用并改变膜结构。我们通过表面等离子体共振表明，哈姆雷特以高亲和力与具有不同酰基链组成和净电荷的表面粘附的单层脂质囊泡结合。荧光成像显示哈姆雷特在囊泡的膜中积累并扰乱其结构，导致膜流动性增加。此外，哈姆雷特在中性pH和生理条件下破坏膜的完整性，如荧光团泄漏实验所示。这些影响没有发生与天然HLA或组成型未折叠的Cys-Ala HLA突变体（rHLAall-Ala）。哈姆雷特还结合到由完整肿瘤细胞形成的质膜囊泡上，在某些膜区域积累，但复合物不被这些囊泡或合成膜囊泡内化。结果说明了部分未折叠HLA的脂肪酸结合和脂肪酸游离形式之间的膜亲和力的差异，并表明哈姆雷特通过需要蛋白质和脂肪酸两者的机制接合膜。此外，哈姆雷特结合改变了膜的形态并损害其完整性，表明膜扰动可能是诱导细胞死亡的初始步骤。
Cell membrane interactions rely on lipid bilayer constituents and molecules inserted within the membrane, including specific receptors. HAMLET (human α-lactalbumin made lethal to tumor cells) is a tumoricidal complex of partially unfolded α-lactalbumin (HLA) and oleic acid that is internalized by tumor cells, suggesting that interactions with the phospholipid bilayer and/or specific receptors may be essential for the tumoricidal effect. This study examined whether HAMLET interacts with artificial membranes and alters membrane structure. We show by surface plasmon resonance that HAMLET binds with high affinity to surface adherent, unilamellar vesicles of lipids with varying acyl chain composition and net charge. Fluorescence imaging revealed that HAMLET accumulates in membranes of vesicles and perturbs their structure, resulting in increased membrane fluidity. Furthermore, HAMLET disrupted membrane integrity at neutral pH and physiological conditions, as shown by fluorophore leakage experiments. These effects did not occur with either native HLA or a constitutively unfolded Cys-Ala HLA mutant (rHLAall-Ala). HAMLET also bound to plasma membrane vesicles formed from intact tumor cells, with accumulation in certain membrane areas, but the complex was not internalized by these vesicles or by the synthetic membrane vesicles. The results illustrate the difference in membrane affinity between the fatty acid bound and fatty acid free forms of partially unfolded HLA and suggest that HAMLET engages membranes by a mechanism requiring both the protein and the fatty acid. Furthermore, HAMLET binding alters the morphology of the membrane and compromises its integrity, suggesting that membrane perturbation could be an initial step in inducing cell death.
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影响因子：
4.8
作者：
BANUELOS, S;MUGA, A
通讯作者：
MUGA, A
影响因子：
2.9
作者：
BURGESS, SW;MCINTOSH, TJ;LENTZ, BR
通讯作者：
LENTZ, BR
影响因子：
5.6
作者：
Halskau, O;Underhaug, J;Martínez, A
通讯作者：
Martínez, A
DOI：
10.1016/0005-2736(85)90084-7
发表时间：
1985-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
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通讯作者：
JANOFF, AS
影响因子：
16.6
作者：
Bauer, Brigitte;Davidson, Max;Orwar, Owe
通讯作者：
Orwar, Owe