Rhodamines are a group of fluorescent dyes that belong to the family of fluorone dyes. Rhodamine dyes have a 300-fold higher sensitivity than analogous coumarin derivatives and generate less background noise. Due to the red-shifted excitation and emission wavelengths, Rhodamine 110 interferes less with components of color-based assays compared to coumarin derivatives such as AMC (AMC: Ex 380 nm / Em 460 nm vs. Rh110: Ex 492 nm / Em 529 nm).

Many Rhodamine 110 protease substrates are symmetric. In symmetric substrates, the dye is bound via both amino functionalities to short identical amino acid sequences (bisamide). Cleavage of the first peptide bond to Rhodamine 110 significantly increases the compound’s fluorescence by approx. 3500, which is one of the advantages of these substrates. After the first proteolytic cleavage, symmetric Rhodamine substrates undergo a second proteolytic cleavage step, which complicates the determination of protease kinetics.

In our new asymmetric substrates, one peptide sequence is replaced by a blocking group such as D-Proline, so that only one proteolytic cleavage per substrate molecule occurs. This results in significantly simpler kinetics upon analysis, while retaining all the advantages listed above for the symmetric substrates.

→ Available quantities: 1 to 100 mg; for bulk quantities, please inquire.
→ Rh110 substrates for other protease targets and/or with different blocking groups can be provided on demand. Contact us and send us sequence and quantity of your interest.

References

• Chemical Synthesis of Ubiquitin, Ubiquitin-Based Probes, and Diubiquitin; F. El Oualid, R. Merkx, R. Ekkebus, D. S. Hameed, J. J. Smit, A. de Jong, H. Hilkmann, T. K. Sixma and H. Ovaa; Angewandte Chemie International Edition 2010; 49: 10149-10153. doi:10.1002/anie.201005995
• Development of Novel Assays for Proteolytic Enzymes Using Rhodamine-Based Fluorogenic Substrates; S. K. Grant, J. G. Sklar and R. T. Cummings; Journal of Biomolecular Screening 2002; 7: 531-540. doi:10.1177/1087057102238627
• A sensitive fluorescence intensity assay for deubiquitinating proteases using ubiquitin-rhodamine110-glycine as substrate; U. Hassiepen, U. Eidhoff, G. Meder, J.-F. Bulber, A. Hein, U. Bodendorf, E. Lorthiois and B. Martoglio; Analytical Biochemistry 2007; 371: 201-207. doi:10.1016/j.ab.2007.07.034
• Rhodamine-based compounds as fluorogenic substrates for serine proteinases; S. P. Leytus, L. L. Melhado and W. F. Mangel; Biochemical Journal 1983; 209: 299-307. doi:10.1042/bj2090299
• Structural Determinants of MALT1 Protease Activity; C. Wiesmann, L. Leder, J. Blank, A. Bernardi, S. Melkko, A. Decock, A. D'Arcy, F. Villard, P. Erbel, N. Hughes, F. Freuler, R. Nikolay, J. Alves, F. Bornancin and M. Renatus; Journal of Molecular Biology 2012; 419: 4-21.
  doi:10.1016/j.jmb.2012.02.018