Cary P D, Crane-Robinson C, Bradbury E M, Dixon G H
Eur J Biochem. 1982 Sep;127(1):137-43. doi: 10.1111/j.1432-1033.1982.tb06847.x.
The trypsin-sensitive N-terminal domain of histone H4 (residues 1-19) contains four acetylation sites at residues 5, 8, 12 and 16 and may play a separate role in chromatin structure from the remainder of the H4 chain. High-resolution proton NMR has been used to probe the DNA-binding of this H4 domain using the peptides (4-17), (1-23) and (1-37). Binding strength is in the order (1-37) greater than (1-23) greater than (4-17) but is weak even for (1-37). The observed weak binding correlates with arginine rather than lysine content and marked changes in the glycine resonance indicate the involvement of the peptide backbone in binding. When peptides (1-23) and (4-17) are fully acetylated with acetic anhydride, this weak binding is totally abolished. Circular dichroism indicates that neither acetylated nor unacetylated peptides take up any secondary structure. The results are consistent with the view that acetylation of H4 in vivo lifts the N-terminal domain off the DNA and thereby promulgates a major structural change in the chromatin.
组蛋白H4的胰蛋白酶敏感N端结构域（第1 - 19位氨基酸残基）在第5、8、12和16位氨基酸残基处含有四个乙酰化位点，并且在染色质结构中可能发挥与H4链其余部分不同的作用。高分辨率质子核磁共振已被用于通过肽段（4 - 17）、（1 - 23）和（1 - 37）来探测该H4结构域与DNA的结合情况。结合强度顺序为（1 - 37）大于（1 - 23）大于（4 - 17），但即使是（1 - 37）的结合也很弱。观察到的弱结合与精氨酸含量而非赖氨酸含量相关，并且甘氨酸共振的显著变化表明肽主链参与了结合。当肽段（1 - 23）和（4 - 17）用乙酸酐完全乙酰化时，这种弱结合完全消失。圆二色性表明乙酰化和未乙酰化的肽段均未呈现任何二级结构。这些结果与以下观点一致，即体内H4的乙酰化使N端结构域脱离DNA，从而引发染色质中的重大结构变化。
