小白鼠心肌核DNA片段中的基因表达的分子开关的研究

原位染色发现，LDH（1－5）…nNAD^ (LDH：乳酸脱氢酶，NAD^ ，氢化型辅酶）可以进入核孔，可能与自己编码基因特异结合，体外表达实验中，稀释心肌DNA片段，促进LDH／DNA表达LDH（1－5），LDH（1－5）表达量与LDH／DNA中可解离的LDH（1－5）量呈正相关性。同位素^14C标记L if impglk ty LDH(1-5)…NAD^ 可以抑制LDH／DNA体外表达，LDH（1－5）表达抑制量与加入LDH（1－5）…nNAD^ 量呈正相关性，AFM直接观察到活性基因两头的调控序列可能结合自己编码的蛋白等活性因子，基因表达与调控的分子开关主要是自己编码的蛋白等活性因子，展示了未来运用AFM和同位素标记法相结合研究生物学反应的前景。

The Study on the Molecular Switch of Gene Expression of the Mouse Heart Nuclear DNA Fragments

It is observed by in situ stain that LDH(1-5)…nNAD+ can probabl y enter the nucleopore and bind specifically with the gene that encodes itself. During the i n vitro expression, the dilution of heart nuclear DNA fragments could enhance th e expression activity of LDH/DNA*, the amount of expressed LDH(1-5) is in propo rtion to the amount of dissociable LDH(1-5) on the LDH/DNA*. With the int egrati on of the 14　C-Leu to the protein, it is also observed that the additio n of LDH (1-5)…nNAD+ may suppress the in vitro expression activity of LDH/DNA* and the decreased amount of expressed LDH(1-5) is in proportion to the amount of a dded L DH(1-5)…nNAD+. AFM observation shows that the regulation sequence at t he two e nds of the active genes may bind with such active factors as the proteins encode d by the genes themselves.