Oñaderra M, Monsalve R I, Mancheño J M, Villalba M, Martinez del Pozo A, Gavilanes J G, Rodriguez R
Departamento de Bioquímica y Biología Molecular, Facultad de Química, Universidad Complutense, Madrid, Spain.
Eur J Biochem. 1994 Oct 15;225(2):609-15. doi: 10.1111/j.1432-1033.1994.00609.x.
Sin a I, the major allergen from mustard seeds, interacts with acid phospholipid vesicles. The protein binds to dimyristoylglycerophosphoglycerol vesicles with an apparent dissociation constant of approximately 2.4 microM, the number of phospholipid molecules affected by one protein molecule being approximately 20. Sin a I promotes an increase in the light scattering of a vesicle suspension. This process becomes saturated at approximately a lipid/protein molar ratio of 20:1. Sin a I also modifies the thermotropic behaviour of the negatively charged vesicles, which has been studied by measuring the fluorescence polarization of the probe 1,6-diphenyl-1,3,5-hexatriene incorporated into the hydrophobic core of the bilayer. Sin a I also promotes lipid mixing between vesicles. This mixing has been analyzed by measuring the variation of the fluorescence energy transfer between N-(7-nitro-2-1,3-benzoxadiazol-4-yl)-dimyristoylglycerophosphoe thanolamine (donor) and N-(lissamine rhodamine B sulphonyl)-PtdEtn (acceptor) incorporated into dimyristoylglycerophosphoglycerol vesicles. This effect is also corroborated by observing a single thermotropic transition in a mixture of independent dipalmitoylglycerophosphoglycerol and dimyristoylglycerophosphoglycerol vesicles when Sin a I is added to the lipid suspension. The allergen promotes release of aqueous contents of PtdGro vesicles, as determined by an aminonaphthalenetrisulfonic acid/p-xylylenebis(pyridinium)bromide dequenching assay. This study shows that the allergen Sin a I is able to interact with membrane lipids. This interaction is discussed in terms of its potential involvement in the allergenicity of this protein.
来自芥菜籽的主要过敏原Sin a I与酸性磷脂囊泡相互作用。该蛋白与二肉豆蔻酰甘油磷酸甘油囊泡结合，表观解离常数约为2.4微摩尔，一个蛋白分子影响的磷脂分子数约为20。Sin a I促进囊泡悬浮液的光散射增加。该过程在脂质/蛋白摩尔比约为20:1时达到饱和。Sin a I还改变了带负电荷囊泡的热致行为，这是通过测量掺入双层疏水核心的探针1,6-二苯基-1,3,5-己三烯的荧光偏振来研究的。Sin a I还促进囊泡之间的脂质混合。这种混合已通过测量掺入二肉豆蔻酰甘油磷酸甘油囊泡中的N-(7-硝基-2,1,3-苯并恶二唑-4-基)-二肉豆蔻酰甘油磷酸乙醇胺（供体）和N-(丽丝胺罗丹明B磺酰基)-磷脂酰乙醇胺（受体）之间荧光能量转移的变化进行了分析。当将Sin a I添加到脂质悬浮液中时，在独立的二棕榈酰甘油磷酸甘油和二肉豆蔻酰甘油磷酸甘油囊泡混合物中观察到单一的热致转变，这也证实了这种效应。通过氨基萘三磺酸/对二甲苯双(吡啶鎓)溴化物去猝灭测定法确定，该过敏原促进磷脂酰甘油囊泡中水性内容物的释放。这项研究表明，过敏原Sin a I能够与膜脂相互作用。根据其可能参与该蛋白的致敏性对这种相互作用进行了讨论。
