DNA纤维热变性过程的差示扫描量热分析  

Differential Scanning Calorimetric Study on the Thermo-denaturation Process of DNA Fibers

作　　者：余多慰[1] 陈婉蓉[1] 

机构地区：[1]南京师范大学生物系

出　　处：《分析测试学报》1998年第2期5-7,共3页Journal of Instrumental Analysis

基　　金：江苏省科委自然科学基金

摘　　要：鲱精ＤＮＡ纤维的差示扫描量热（ＤＳＣ）谱中，除存在一个高温区的变性峰以外，还有３个低温区的吸热峰，类似于蛋白质ＤＳＣ分析中出现的“变性前峰”。经过２５３１５Ｋ（－２０℃）冻结处理的ＤＮＡ纤维，空间结构稳定性提高，变性前峰峰温增加４～８Ｋ。冻结与非冻结两类样品中，变性前峰的焓值分别为－１０２５３和－７７６５ｋＪ·ｍｏｌ－１。作者探讨了ＤＮＡ变性前峰的成因，并认为ＤＮＡ变性过程中的多元性可能与碱基序列特异性有关。The differential scanning calorimetric analysis(DSC)of herring sperm DNA fibers is described. The thermograms show one thermo-denaturation peak(TP)in the high temperature region and three endothermic peaks in lower temperature regions, that are similar to the ″pre-thermo-denaturation peak″(PTP) in the DSC thermograms of proteins. As compared with non_frozen fibers, a freezing treatment of the fibers at -20 ℃ raised the spatial structure stability of DNA fibers, and raised the denaturation temperature(T)of the PTPs as well by 4～8 ℃.The PTP enthalpies (ΔH)of frozen and non_frozen samples equal to -10253 and -7765 kJ·mol-1,respectively. As the authors suggested, the multistage process of thermal denaturation can be correlated with the characteristic of nucleotide sequence.

关 键 词：热变性 鲱精DNA纤维 DNA纤维 DSC 

分 类 号：Q523.02[生物学—生物化学]