Rhodamine 110 (Rh110)-labeled peptides are used in the study of a number of protease activity, such as cysteine aspartate-specific proteases and serine proteases.^1-2 Rhodamine 110 (Figure 1) contains two amino groups available for conjugation to the C-terminal end of a peptide or amino acid. Protease cleavage of the non-fluorescent bis-substituted rhodamine 110 peptide derivatives result in monosubstituted rhodamine 110 and free rhodamine 110, both of which are fluorescent.¹ Fluorescence intensity can therefore be correlated to protease activity.

Rhodamine110 conjugated to charged amino acids are generally cell permeable. As a results, these substrates can be used in intact cells for applications such as flow cytometry.² Rhodamine labeled peptides affords significant advantages over AFC or AMC labeled peptides in that Rh110 emits in the green range (Ex/Em=501/527nm), while AMC (Ex/Em=340/440 nm) and AFC (Ex/Em=370/500 nm) emits in the blue range. Autofluorescence interference from cellular components is minimal, making the substrates more sensitive. Rhodamine 110-peptide conjugates are also not pH dependent.¹

Figure 1. Molecular structure of Rhodamine 110.

AnaSpec is pleased that our Rhodamine 110 labeled peptides, especially the caspase substrates have long been used and trusted by researchers. As part of our GO™ (catalog) peptides, these peptides are rigorously QC’d (3 times) using mass spec and HPLC (>95% purity). For custom peptide synthesis inquiries, please contact service@anaspec.com. Other labels include our proprietary HiLyte Fluor dyes, classic dyes (FAM, Sulforhodamine 101), pNA, aminoluciferin, and others.

References: