Jovin T M, Geisler N, Weber K
Nature. 1977 Oct 20;269(5630):668-72. doi: 10.1038/269668a0.
The N-terminal fragments (residues 1-51 and 1-59) obtained by selective tryptic cleavage of native lac repressor retain the ability to bind DNA. These fragments (headpieces) are monomeric and form complexes which resemble those of tetrameric repressor with non-operator DNA. But, they do not show the high specificity of repressor for operator sequences. The DNA binding has been demonstrated by filter-binding assay as well as in solution using absorption, circular dichroism, and fluorescence measurements.
通过对天然乳糖阻遏物进行选择性胰蛋白酶切割获得的N端片段（残基1 - 51和1 - 59）保留了结合DNA的能力。这些片段（头部）是单体，形成的复合物类似于四聚体阻遏物与非操纵基因DNA形成的复合物。但是，它们对操纵序列不表现出阻遏物的高特异性。通过滤膜结合试验以及在溶液中利用吸收、圆二色性和荧光测量已证实了DNA结合。
