New ratiometric fluorescent calcium indicators with moderately attenuated binding affinities.
Mono-halogenated derivatives of the calcium indicators fura-2 and indo-1 were synthesized and their spectroscopic properties evaluated. Halogenation ortho or para to the bridging oxygen in the BAPTA nucleus had a more pronounced weakening effect on binding affinity than in the meta position in the fura derivatives. Two new excitation ratioable fluorescent calcium indicators, benzothiaza-1 and 2, were also synthesized. Kd values of 400 nM to 5.3 microM [Ca2+] were observed in these families of new probes.
Gee
K R
KR
Molecular Probes, Inc., Eugene, OR 97402, USA. melodyouellet@probes.com
Archer
E A
EA
Lapham
L A
LA
Leonard
M E
ME
Zhou
Z L
ZL
Bingham
J
J
Diwu
Z
Z
D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D016257:Fura-2 / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
D005456:Fluorescent Dyes; D007211:Indoles; C048960:indo-1; D002118:Calcium; D016257:Fura-2