Biology Reference
In-Depth Information
CO
−
−
O
2
C
−
O
2
C
−
O
2
C
CO
−
CO
−
CO
−
−
O
2
C
CO
−
−
O
2
C
CO
−
−
O
2
C
N
N
N
N
N
N
O
O
O
N
O
O
O
EGTA
BAPTA
Quin2
CO
−
−
O
2
C
−
O
2
C
CO
−
CO
−
CO
−
−
O
2
C
−
O
2
C
N
N
N
N
O
O
O
O
O
N
NH
O
Fura-2
Indo-1
CO
−
CO
−
−
O
2
C
−
O
2
C
CO
−
CO
−
CO
− −
O
2
C
CO
−
−
O
2
C
N
N
N
N
X
O
O
O
O
N
+
O
R
Fluo-
X
R
Rhod-2
O
O
X
2 or
−
8*
3
4
H
H or CH
3
CH
3
CH
3
O
−
N
Cl
F
CO
−
−
O
2
C
CO
− −
O
2
C
N
N
X
O
O
Calcium green-2
Oregon green 488 BAPTA-2
Cl
F
O
O
N
H
N
H
X
X
CO
−
−
O
2
C
O
O
O
X
X
O
O
−
−
O
Fig. 1
Structures of selected fluorescent Ca
2
þ
indicators and the Ca
2
þ
chelators, EGTA, and BAPTA.
All molecules are represented in their polycarboxylate, Ca
2
þ
-sensitive forms. The following conventions
have been used in these structural drawings: (1) Implicit carbon: Every unlabeled vertex, whether
internal or terminal, represents a carbon atom. (2) Implicit hydrogen: Every carbon has a su
cient
number of (undrawn) hydrogens to make the total number of bonds to that carbon equal to 4. (3)
Explicit heteroatoms: non-carbon, non-hydrogen atoms (e.g., O, N) are labeled explicitly; hydrogens
attached to the heteroatom are also explicitly drawn. For example,
Y
OH
is equivalent to