3-(4-Carboxybenzoyl)quinoline-2-carboxaldehyde

3-(4-Carboxybenzoyl)quinoline-2-carboxaldehyde (CBQCA) is a fluorogenic amine labeling dye that is not fluorescent itself, but covalently reacts with primary amines to form fluorescent products.[1] It was first reported in 1991.[2]

CBQCA
Names
IUPAC name
4-(2-Formylquinoline-3-carbonyl)benzoic acid
Other names
CBQCA, ATTO-TAG CBQCA
Identifiers
3D model (JSmol)
  • InChI=1S/C18H11NO4/c20-10-16-14(9-13-3-1-2-4-15(13)19-16)17(21)11-5-7-12(8-6-11)18(22)23/h1-10H,(H,22,23)
    Key: MWNLTKCQHFZFHN-UHFFFAOYSA-N
  • C1=CC=C2C(=C1)C=C(C(=N2)C=O)C(=O)C3=CC=C(C=C3)C(=O)O
Properties
C18H11NO4
Molar mass 305.289 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

CBQCA is largely used in the context of quantifying peptides or proteins. Either cyanide or thiols are required as a co-substrate in the fluorogenic reaction, although thiols also react with and mask the CBQCA aldehyde thereby preventing the fluorogenic reaction against the targeted primary amines.[1] Once bound to protein the excitation wavelength is 465 nm (blue) and the emission wavelength is ~550 nm (green).[3]

Reaction

edit

CBQCA, which is non-fluorescent, reacts with primary amines in the presence of cyanide to form fluorescent products:  

See also

edit

References

edit
  1. ^ a b You, Wendy W.; Haugland, Rosaria P.; Ryan, Diane K.; Haugland, Richard P. (1997). "3-(4-Carboxybenzoyl)quinoline-2-carboxaldehyde, a Reagent with Broad Dynamic Range for the Assay of Proteins and Lipoproteins in Solution". Analytical Biochemistry. 244 (2). Elsevier BV: 277–282. doi:10.1006/abio.1996.9920. ISSN 0003-2697. PMID 9025944.
  2. ^ Liu, Jinping.; Hsieh, You Zoung.; Wiesler, Donald.; Novotny, Milos. (1991-03-01). "Design of 3-(4-carboxybenzoyl)-2-quinolinecarboxaldehyde as a reagent for ultrasensitive determination of primary amines by capillary electrophoresis using laser fluorescence detection". Analytical Chemistry. 63 (5). American Chemical Society (ACS): 408–412. doi:10.1021/ac00005a004. ISSN 0003-2700. PMID 2064006.
  3. ^ Fisher Scientific, Thermo. "CBQCA Protein Quantitation Kit - Product Information" (PDF). Retrieved 7 April 2023.