Klevan L, Schumaker V N
Nucleic Acids Res. 1982 Nov 11;10(21):6809-17. doi: 10.1093/nar/10.21.6809.
The identification of left handed or Z-DNA in solutions of poly d(GC) in high salt suggests that left handed DNA may exist in biological systems if stabilized at lower ionic strength. In the present study we show that binding of polyarginine to the Z form of poly d(GC) results in a protein-Z-DNA complex stable near physiological ionic strength. The percentage of Z-DNA in the low salt polyarginine-poly d(GC) complex was measured from the DNA circular dichroism spectrum. The ratio of Z to B-DNA is a linear function of polyarginine concentration and is sensitive to proteolytic digestion by trypsin. These results suggest that arginine-rich proteins may stabilize Z-DNA in vivo.
在高盐条件下聚 d(GC)溶液中左旋或 Z-DNA 的鉴定表明,如果在较低离子强度下稳定,左旋 DNA 可能存在于生物系统中。在本研究中,我们表明聚精氨酸与聚 d(GC)的 Z 型结合会形成在生理离子强度附近稳定的蛋白质-Z-DNA 复合物。低盐聚精氨酸-聚 d(GC)复合物中 Z-DNA 的百分比通过 DNA 圆二色光谱测量。Z 与 B-DNA 的比例是聚精氨酸浓度的线性函数,并且对胰蛋白酶的蛋白水解消化敏感。这些结果表明富含精氨酸的蛋白质可能在体内稳定 Z-DNA。