BINDING OF ETHIDIUM TO THE NUCLEOSOME CORE PARTICLE .2. INTERNAL AND EXTERNAL BINDING MODES

被引:42
作者
MCMURRAY, CT [1 ]
SMALL, EW [1 ]
VANHOLDE, KE [1 ]
机构
[1] OREGON STATE UNIV,DEPT BIOCHEM & BIOPHYS,CORVALLIS,OR 97331
关键词
D O I
10.1021/bi00237a002
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
We have previously reported that the binding of ethidium bromide to the nucleosome core particle results in a stepwise dissociation of the structure which involves the initial release of one copy each of H2A and H2B (McMurray & van Holde, 1986). In this report, we have examined the absorbance and fluorescence properties of intercalated and outside bound forms of ethidium bromide. From these properties, we have measured the extent of external, electrostatic binding of the dye versus internal, intercalation binding to the core particle, free from contribution by linker DNA. We have established that dissociation is induced by the intercalation mode of binding to DNA within the core particle DNA, and not by binding to the histones or by nonintercalative binding to DNA. The covalent binding of [H-3]-8-azidoethidium to the core particle clearly shows that < 1.0 adduct is formed per histone octamer over a wide range of input ratios. Simultaneously, analyses of steady-state fluorescence enhancement and fluorescence lifetime data from bound ethidium complexes demonstrate extensive intercalation binding. Combined analyses from steady-state fluorescence intensity with equilibrium dialysis or fluorescence lifetime data revealed that dissociation began when approximately 14 ethidium molecules are bound by intercalation to each core particle and < 1.0 nonintercalated ion pair was formed per core particle.
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页码:5644 / 5652
页数:9
相关论文
共 73 条
[1]  
AUSIO J, 1986, BIOCHEMISTRY-US, V26, P1981
[2]  
AUSIO J, 1984, J MOL BIOL, V176, P509
[3]   COMPUTERIZED FLUORESCENCE ANISOTROPY SPECTROMETER [J].
AYRES, WA ;
SMALL, EW ;
ISENBERG, I .
ANALYTICAL BIOCHEMISTRY, 1974, 58 (02) :361-367
[4]  
BAUER WR, 1974, PRINCIPLES NUCLEIC A
[5]  
BLOOMFIELD VA, 1974, PHYSICAL CHEM NUCLEI
[6]  
BOLTON PH, 1978, NUCLEIC ACIDS RES, V5, P4851
[7]   CRYSTALLOGRAPHIC STRUCTURE OF THE OCTAMERIC HISTONE CORE OF THE NUCLEOSOME AT A RESOLUTION OF 3.3 A [J].
BURLINGAME, RW ;
LOVE, WE ;
WANG, BC ;
HAMLIN, R ;
XUONG, NH ;
MOUDRIANAKIS, EN .
SCIENCE, 1985, 228 (4699) :546-553
[8]  
CHENG SW, 1979, APPLIED NONLINEAR AN
[9]  
COTTON RW, 1981, NUCLEIC ACIDS RES, V9, P455
[10]   MOLECULAR STRUCTURAL EFFECTS INVOLVED IN INTERACTION OF QUINOLINEMETHANOLAMINES WITH DNA - IMPLICATIONS FOR ANTIMALARIAL ACTION [J].
DAVIDSON, MW ;
GRIGGS, BG ;
BOYKIN, DW ;
WILSON, WD .
JOURNAL OF MEDICINAL CHEMISTRY, 1977, 20 (09) :1117-1122