期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1973
卷号：70
期号：10
页码：2899-2901
DOI：10.1073/pnas.70.10.2899
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We have studied the low-field proton magnetic resonance spectrum of the double-helical complex of d(A-A-C-A-A) with d(T-T-G-T-T). Well-resolved resonances for the thymidine N3 and the guanosine N1 protons are seen at 1{degrees}C, which broaden by 4{degrees}C and disappear above 9{degrees}C. The actual Tm of the complex was found to be 28{degrees}C by measurement of UV-absorbance change. There are several factors that could limit the observed exchange broadening of the resonance lines; the model that best fits the data is one in which the rate of double-helix dissociation limits the rate of exchange of the H-bonding protons with water.
