Surface change of biological membranes as a possible regulator of membrane-bound enzymes.
Surface change of biological membranes as a possible regulator of membrane-bound enzymes.
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生物膜的表面变化作为膜结合酶的可能调节剂。
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
M. Nałȩcz
中科院分区：
文献类型：
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作者：
L. Wojtczak;M. Nałȩcz
1
昆虫胸肌线粒体甘油-3-磷酸脱氢酶和大鼠肝微粒体芳基硫酸酯酶C被阴离子表面活性剂油酸酯、棕榈酰辅酶A和十二烷基硫酸钠抑制，被阳离子表面活性剂十六烷基三甲基溴化铵和十六烷基氯化吡啶激活。大鼠肝微粒体二甲基苯胺氧化酶被阳离子表面活性剂抑制，被阴离子表面活性剂激活。阴离子表面活性剂可增强NAD+对大鼠肝线粒体颗粒中NADH脱氢酶的抑制作用，而十六烷基三甲基溴化铵可部分解除NAD+的抑制作用。
2
这些表面活性的活化剂和抑制剂改变了酶的表观Km值，但没有改变在无限底物浓度（V值）的活动。
3
这种效果的表面活性剂消失后溶解的膜和重新出现后，将溶解的酶到磷脂囊泡。
4
阳离子表面活性剂减少，而阴离子表面活性剂增加线粒体、亚线粒体颗粒和微粒体的表面负电荷和表面电位，通过颗粒的自由电泳和8-苯胺基-1-萘磺酸盐的结合来测量。
5
基于Km变化和表面电位变化的计算与表面电荷密度的变化改变膜附近的底物和/或产物的局部浓度的假设一致。
6
影响生物膜表面电荷的因素在控制膜结合酶的活性中可能起的作用进行了讨论。
1
Glycerol-3-phosphate dehydrogenase of insect thoracic muscle mitochondria and arylsulphatase C of rat liver microsomes were inhibited by anionic surface-active agents oleate, palmitoyl-CoA and sodium dodecylsulphate, and activated by cationic surfactants cetyltrimethylammonium bromide and cetylpyridinium chloride. Dimethylaniline oxidase of rat liver microsomes were inhibited by cationic surfactants and activated by anionic surfactants. The inhibition of NADH dehydrogenase of rat liver submitochondrial particles by NAD+ was potentiated by the anionic surfactants and partly released by cetyltrimethylammonium bromide.
2
These surface-active activators and inhibitors altered apparent Km values of the enzymes but did not change the activities at infinite substrate concentration (V values).
3
This effect of surfactants disappeared after solubilization of the membranes and re-appeared after incorporating the solubilized enzyme into phospholipid vesicles.
4
Cationic surfactants decreased whereas anionic surfactants increased the negative surface charge and surface potential of mitochondria, submitochondrial particles and microsomes, as measured by free electrophoresis of the particles and binding of 8-anilino-1-naphthalene sulphonate.
5
Calculations based on Km change and the change of surface potential agree well with the assumption that a change of the surface charge density alters local concentrations of the substrates and/or the products in the vicinity of the membrane.
6
Possible role of factors affecting the surface charge of biological membranes in controlling the activity of membrane-bound enzymes is discussed.