Skip to main content
. Author manuscript; available in PMC: 2015 Jan 19.
Published in final edited form as: Mol Imaging Biol. 2014 Apr;16(2):152–157. doi: 10.1007/s11307-013-0680-5

Figure 3.

Figure 3

Detection of CPG2-mediated cleavage of 3,5-DFBGlu with CEST-MR. (a) Evolution of the CEST signal over time, following the addition of 10mM 3,5-DFBGlu to extracts of WiDr cells engineered to express CPG2 (CPG2 WiDr) or β-galactosidase (LacZ WiDr), at pH 7 and 37°C. CEST signal is expressed as (M0 − Msat(t))/M0, where M0 and Msat(t) are the bulk water signal acquired without and with saturation (at +2ppm and +3ppm) at a time t after addition of 3,5-DFBGlu. (b) GluCEST signal from a 5mM solution of 3,5-DFBGlu measured 2h following the addition of 10mU of purified CPG2 or enzyme buffer. The GluCEST signal was calculated as MTRassym = (M−3ppm − M+3ppm) /M0 , where M−3ppm and M+3ppm represent the bulk water signals acquired with selective RF saturation at ±3ppm resonance offset from the water frequency. (*** p<0.005, Student’s 2-tailed unpaired t-test with a 5% level of significance, n=3)