Acta Phys. -Chim. Sin. ›› 1993, Vol. 9 ›› Issue (03): 295-298.doi: 10.3866/PKU.WHXB19930303

• Communication • Previous Articles     Next Articles

The Energy Transfer From Triplex dA10·2dT10 to Bound Ethidium Bromide

Bai Chun-Li; Fang Ye; Cao En-Hua; Zhang Ping-Cheng; He Yu-Jian; Tang You-Qi   

  1. Institute of Chemistry, Academia Sinica, Beijing 100080; Institute of Biophysics, Academia Sinica, Beijing 100101
  • Received:1993-01-03 Revised:1993-02-09 Published:1993-06-15
  • Contact: Fang Ye

Abstract: The energy transfer from triplex dA_(10)·2dT_(10) or duplex dA_(10)·dA_(10) to ethidium bromide in the 10 mmol·L~(-1) phosphate buffer (pH=7.1) has been investigated. The apparent relative fluorescence quantum yield as a function of excitation wavelength is observed, but the increase in quantum yield in case of the triplex is lower than that for the duplex. This result not only provides strong evidence for intercalative binding of ethidium to both duplex and triplex forms of dA_(10) and dT_(10), but also indicates that binding to the triplex form results in substantially smaller energy transfer than binding to the duplex.

Key words: Triplex d(A)10·2dT10, Ethidium bromide, Energy transfer