Skip to main content
. 2010 May 10;38(17):5692–5705. doi: 10.1093/nar/gkq350

Figure 4.

Figure 4.

Analysis of the exonuclease activity by using FT-ICR MS. (A) The nomenclature scheme used for oligonucletide ions (72). The four possible cleavages are indicated by the lower case letters a, b, c and d for ions containing the 5′-OH group and w, x, y and z for ions containing the 3′-OH group. The numerical subscripts indicate the number of bases from the respective termini. FT-ICR MS can achieve the simultaneous identification of these ions. (B) The deconvoluted mass spectra of the product ssDNAs of TTHB178. The 21-mer ssDNA (21f) was reacted with 3-μM TTHB178 at 37°C. The product ssDNAs were purified as described in the ‘Materials and Methods’ section and then analysed by using FT-ICR MS. The reaction time is shown in the panel. (C) The measured and theoretical masses of each peak (named A to Q) are listed and the corresponding sequences are also shown as the ‘identified sequence’. The measured mass coincided with the theoretical mass ∼10-ppm mass measurement accuracy.