EXPOSED HYDROPHOBIC REGIONS IN HISTONE OLIGOMERS STUDIED BY FLUORESCENCE
EXPOSED HYDROPHOBIC REGIONS IN HISTONE OLIGOMERS STUDIED BY FLUORESCENCE
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DOI：
10.1016/0005-2795(80)90287-1
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发表时间：
1980-01-01
期刊：
影响因子：
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通讯作者：
DOLCAGUASCH, M
中科院分区：
文献类型：
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作者：
RAMONDABAN, J;DOLCAGUASCH, M
研究了疏水荧光探针1-苯基-8-苯基-8-磺酸(ANS)与组蛋白低聚体和[小牛胸腺]组蛋白H1的相互作用。组蛋白H.nu对ANS荧光的增强作用。(组蛋白H_2A、H_2B、H_3和H_4的大致等摩尔混合物)在2.0M氯化钠、pH 7.5中，比组蛋白H1在相同条件下产生的组蛋白高。H1-ANS复合体的最大发射波长大于H.nu-ANS复合体的最大发射波长，这表明组蛋白H1的疏水性弱于组蛋白H.nu。ANS浓度的增加导致H.nu-ANS复合体的最大发射红移，表明ANS结合位点的异质性。H_2A-H_2B和H_3-H_4络合物对ANS荧光的增强作用相似。组蛋白N端序列的胰酶消化。产生ANS荧光强度的微小变化。组蛋白H.nu的疏水区。ANS结合的部分不位于组蛋白序列的N-末端。这些暴露的疏水性区域在维持染色质结构方面可能是重要的。
The interaction of the fluorescent hydrophobic probe 1-anilinoanaphthalene-8-sulfonate (ANS) with histone oligomers and with [calf thymus] histone H1 was studied. The enhancement of ANS fluorescence produced by histones H.nu. (a roughly equimolar mixture of histones H2A, H2B, H3 and H4) in 2.0 M NaCl, pH 7.5, is higher than that produced by histone H1 under identical conditions. The fact that the wavelength of maximum emission of the H1-ANS complex is larger than that of H.nu.-ANS complex indicates that histone H1 has a weaker hydrophobic character than histones H.nu.. The increase in ANS concentration produces a red shift of the emission maximum of the H.nu.-ANS complex, indicating heterogeneity in the ANS binding sites. Both the H2A-H2B and the H3-H4 complexes cause similar enhancement of the ANS fluorescence. Trypsin digestion of N-terminal sequences of histones H.nu. produces small changes in the intensity of ANS fluorescence. The hydrophobic regions of histones H.nu. to which ANS binds are not located in the N-terminal portions of histone sequences. These exposed hydrophobic regions may be important in the maintenance of chromatin structure.