Figure 2.

NMR study of hT25 DNA sequence by mutation and methylation. a, imino proton NMR spectra of four mutants, hT25-m1, hT25-m2, hT25-m3, and hT25-m4, in the presence of 150 mm K⁺, as shown in descending order. The quadruplex characters were detected in the spectra of hT25-m2 and hT25-m4. b, imino proton NMR spectra of hT25-Me, hT25-Me(2,3), hT25-Me(1,4), hT25-Me(1), and hT25-Me(4) for hT25 and hT25-m1-Me(4) for hT25-m1 in the presence of 150 mm K⁺, as shown in descending order. Their sequences are listed in supplemental Table S1.