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Structure of DAPA
The structure of dansylarginine N-(3-ethyl-1,5-pentanediyl)amide (DAPA) is illustrated. DAPA is a potent inhibitor of thrombin which exhibits unique changes in its fluorescent properties when bound to thrombin.

  • Prices $124.00/1mg ($112.00/min. 5), $133.00/1 mg ($120.00/min. 5)
    Sizes 1mg, 1 mg
    Formulation H2O
    Molecular Weight
    Storage -80°C
    Purity HPLC and TLC analysis
    Assay N/A
    Shelf Life (properly stored) 12 months
    Chemical Formula

Dansylarginine N-(3-ethyl-1,5-pentanediyl)amide, more commonly referred to as DAPA, is a potent (Ki=10-7M) and specific synthetic thrombin inhibitor (1). Of special interest are the unique fluorescent properties contributed by the dansyl moiety of DAPA. When bound to thrombin, the fluorescence intensity and lifetime of the dansyl moiety are increased three fold. The enhancement of fluorescence intensity, coupled with its inhibitory properties, have made this compound extremely useful for studies involving thrombin generation (2-7). In addition to an increase in fluorescence intensity and lifetime, there is a decrease in depolarization of the excitation signal which also supports fluorescence polarization studies.

The inhibitor properties of DAPA alone have been useful in a variety of applications. DAPA is routinely used as a protease inhibitor during the isolation of proteins that are susceptible to thrombin cleavage. Furthermore, by eliminating the feedback of thrombin activity during prothrombin activation, the isolation of reaction intermediates such as fragment 1.2, and meizothrombin have been made possible (7).

DAPA is synthesized according the procedure described by Nesheim, et al. (1). HPLC, TLC and spectral analyses are used to determine the purity of the final product. DAPA is supplied in water. When properly stored at -20°C and protected from light, the compound is stable for many years.

Formula C25H39O3N6S1Cl1 (reference #1)
Dansylarginine N-(3-ethyl-1,5-pentanediyl)amide
Molecular weight 539 g/mole (1)
Extinction coefficient
1 %
1 c m, 330 nm
= 4010 (1)
Special properties A specific and potent thrombin inhibitor (Ki = 10-7M). Exhibits a 3-fold increase in fluorescence intensity and lifetime when bound to thrombin.
  1. Nesheim, M.E., et al., Biochemistry, 18, 996 (1979).
  2. Nesheim, M.E., et al., J. Biol. Chem., 254, 10952 (1979).
  3. Hibbard, L.S., et al., Biochemistry, 21, 2285 (1982).
  4. Nesheim, M.E. and Mann, K.G., J. Biol. Chem., 258, 5386 (1983).
  5. Krishnaswamy, S., et al., J. Biol. Chem., 261, 8977 (1986).
  6. Krishnaswamy, S., et al., J. Biol. Chem., 262, 3291 (1987).
  7. Doyle, M.F. and Mann, K.G., J. Biol. Chem., 265, 10693 (1990).
  1. Bos, M., et al., Blood. 2009 114: 686-692.
  2. Majumder, R., et al., Blood. 2008 112: 2795-2802.

This publication list is not all encompassing, and is only meant to provide limited examples of how Haematologic Technologies' products are used. We encourage you to search the literature for other examples pertinent to your experimentation, and to contact us with any technical questions.