Hansma H G, Golan R, Hsieh W, Lollo C P, Mullen-Ley P, Kwoh D
Department of Physics, University of California, Santa Barbara, CA 93106, USA.
Nucleic Acids Res. 1998 May 15;26(10):2481-7. doi: 10.1093/nar/26.10.2481.
The atomic force microscope (AFM) was used to assay the extent of DNA condensation in approximately 100 different complexes of DNA with polylysine (PL) or PL covalently attached to the glycoproteins asialoorosomucoid (AsOR) or orosomucoid (OR). The best condensation of DNA was obtained with 10 kDa PL covalently attached to AsOR, at a lysine:nucleotide (Lys:nt) ratio of 5:1 or higher. These conditions produce large numbers of toroids and short rods with contour lengths of 300-400 nm. Some DNA condensation into shortened thickened structures was seen with 10 kDa PL attached to AsOR at Lys:nt ratios of 1.6:1 and 3:1. Some DNA condensation was also seen with 4 kDa PL at Lys:nt ratios of 3:1 and higher. Little DNA condensation was seen with PL alone or with PL convalently attached to OR at Lys:nt ratios up to 6:1. AsOR-PL enhanced gene expression in the mouse liver approximately 10- to 50-fold as compared with PL alone.
原子力显微镜（AFM）用于分析DNA与聚赖氨酸（PL）或共价连接到糖蛋白去唾液酸血清类黏蛋白（AsOR）或血清类黏蛋白（OR）形成的约100种不同复合物中DNA的凝聚程度。当10 kDa的PL共价连接到AsOR上，赖氨酸与核苷酸（Lys:nt）比例为5:1或更高时，可实现最佳的DNA凝聚。这些条件下会产生大量的环形结构和轮廓长度为300 - 400 nm的短棒状结构。当10 kDa的PL以1.6:1和3:1的Lys:nt比例连接到AsOR上时，可观察到一些DNA凝聚成缩短的加厚结构。当4 kDa的PL以3:1及更高的Lys:nt比例存在时，也能观察到一些DNA凝聚。单独的PL或共价连接到OR上且Lys:nt比例高达6:1的PL，几乎没有观察到DNA凝聚现象。与单独的PL相比，AsOR - PL使小鼠肝脏中的基因表达增强了约10至50倍。
