Structural Transitions in Complementary G-Rich and C-Rich Strands and Their Mixture at Various pH Conditions.

We used circular dichroism spectroscopy, UV spectrophotometry, and differential scanning calorimetry to investigate pH-dependent structural transitions in an equimolar mixture of complementary G-rich d[5'-A(GGGTTA)GGG-3'] (TelG) and C-rich d[3'-T(CCCAAT)CCC-5'] (TelC) human telomeric DNA strands. Our studies were conducted at neutral (pH 7.0) and slightly acidic (pH 5.