{"product_id":"dabcyl-ktsavlqsgfrkm-glu-edans-fret-peptide-substrate-1","title":"Dabcyl-KTSAVLQSGFRKM-Glu(Edans) FRET Peptide Substrate","description":"\u003cdiv style=\"max-width:1400px; margin:0 auto; padding:40px 20px; font-family:'Open Sans',sans-serif; font-weight:300; background:#fff; color:#333; font-size:0.95rem; box-sizing:border-box;\"\u003e\n  \u003cdiv style=\"display:flex; flex-direction:column; gap:20px;\"\u003e\n\u003ch2 style=\"margin:0; font-weight:600;\"\u003eDabcyl-KTSAVLQSGFRKM-Glu(Edans) FRET Peptide Substrate – Catalog #B2026695\u003c\/h2\u003e\n\u003cp\u003eDabcyl-KTSAVLQSGFRKM-Glu(Edans) is a dual-labeled fluorescent peptide designed for continuous FRET-based enzyme assays. It carries a Dabcyl quencher group at the N-terminus and the EDANS fluorophore conjugated to a C-terminal glutamic acid residue (Glu(Edans)). The peptide sequence KTSAVLQSGFRKM lies between these fluorophores. Supplied as 1 mg of lyophilized powder, this substrate is widely used to measure protease activity in real time, as peptide cleavage separates the fluorophore and quencher, resulting in a large increase in EDANS fluorescence.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto; max-width:100%; margin-bottom:20px;\"\u003e\n\u003ctable style=\"width:100%; max-width:640px; border-collapse:collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eCatalog number:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eB2026695\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eLot number:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eBatch dependent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eExpiration Date:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eBatch dependent\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eAmount:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003e1 mg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eSupplied as:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eLyophilized powder\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eLabel (N-terminus):\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eDabcyl (quencher)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eLabel (C-terminus):\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eEDANS on Glu (fluorophore, Ex ~330 nm \/ Em ~480 nm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003ePeptide sequence:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eKTSAVLQSGFRKM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eApplications:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eProtease activity assays, enzyme kinetics (continuous fluorescence), specificity profiling, drug screening, real-time kinetic measurements\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eStorage:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003e−20°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eKeywords:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eDabcyl-EDANS peptide, FRET substrate, protease substrate, fluorescent peptide, Edans peptide, Dabcyl peptide, enzyme assay substrate, continuous fluorescence assay\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"border-bottom:1px solid #ddd;\"\u003e\n\u003ctd style=\"width:150px; padding:6px 10px 6px 0; vertical-align:top;\"\u003e\u003cstrong\u003eGrade:\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:6px 0;\"\u003eBiotechnology grade. All products are highly pure. All solutions are made with Type I ultrapure water (resistivity \u0026gt;18 MΩ-cm) and are filtered through 0.22 um.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eScientific Overview\u003c\/h3\u003e\n\u003cp\u003eFRET (fluorescence resonance energy transfer) peptides leverage the spectral overlap between a donor fluorophore's emission and an acceptor quencher's absorption. In this substrate, EDANS (5-((2-aminoethyl)amino)naphthalene-1-sulfonic acid) serves as the donor fluorophore with excitation around 330 nm and emission around 480 nm. Dabcyl (4-((4-(dimethylamino)phenyl)azo)benzoic acid) is a nonfluorescent quencher whose absorption overlaps the EDANS emission spectrum. When the peptide is intact, FRET efficiently quenches EDANS fluorescence. Protease cleavage within the sequence KTSAVLQSGFRKM separates Dabcyl and EDANS, eliminating FRET and rapidly restoring fluorescence. This change can be monitored continuously in real time, making FRET peptides ideal for kinetic measurements of protease activity, inhibitor potency, and substrate specificity.\u003c\/p\u003e\n\u003cp\u003eKey applications include:\u003c\/p\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003eContinuous fluorescence assays for protease activity and kinetics\u003c\/li\u003e\n\u003cli\u003eHigh-throughput substrate specificity screening\u003c\/li\u003e\n\u003cli\u003eDrug discovery: protease inhibitor potency testing\u003c\/li\u003e\n\u003cli\u003eReal-time enzyme kinetic measurements compatible with plate readers and spectrofluorimeters\u003c\/li\u003e\n\u003cli\u003eResearch into protease mechanism and cleavage preferences\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eUsage \u0026amp; Handling Guidance\u003c\/h3\u003e\n\u003cp\u003eResuspend the lyophilized powder in assay buffer (phosphate, Tris, or HEPES buffer at pH 7–8 is typical) immediately before use. FRET peptide substrates are most sensitive in assays with minimal background fluorescence; perform measurements in black, low-background wells or cuvettes. Quench and fluorescence are sensitive to pH; buffer pH should match the protease's optimal pH for activity.\u003c\/p\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eReconstitution:\u003c\/strong\u003e Dissolve in buffer to 0.1–10 μM (concentration depends on the protease and assay sensitivity desired).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFluorescence measurement:\u003c\/strong\u003e Excite EDANS at ~330 nm; monitor emission at ~480 nm (exact wavelengths depend on the instrument).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eKinetics:\u003c\/strong\u003e Add enzyme to the substrate solution and follow the increase in fluorescence over time. Reaction rates are typically linear for the first 10–30% product formation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStorage of stock:\u003c\/strong\u003e The lyophilized substrate is stable at −20°C. Once reconstituted, working solutions should be used promptly or stored at 2–8°C for short term.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eWhat You Get\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003e1 mg of dual-labeled FRET peptide substrate, lyophilized\u003c\/li\u003e\n\u003cli\u003eDabcyl quencher at the N-terminus\u003c\/li\u003e\n\u003cli\u003eEDANS fluorophore at the C-terminus (Glu(Edans))\u003c\/li\u003e\n\u003cli\u003eOptimized for continuous protease assays and kinetic studies\u003c\/li\u003e\n\u003cli\u003eFor research use only (RUO)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eWhy Researchers Choose It\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003eRobust FRET pair with large dynamic range (on\/off ratio) upon cleavage\u003c\/li\u003e\n\u003cli\u003eEnables real-time, kinetic measurements without stopping the reaction\u003c\/li\u003e\n\u003cli\u003eSimple readout: fluorescence increase is directly proportional to product formation\u003c\/li\u003e\n\u003cli\u003eCompatible with standard plate reader and spectrofluorimeter optics\u003c\/li\u003e\n\u003cli\u003eProven design used in hundreds of published protease assays\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"margin-top:30px;\"\u003eFrequently Asked Questions (FAQ)\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat happens when the protease cleaves the substrate?\u003c\/strong\u003e\u003cbr\u003eCleavage separates the Dabcyl quencher and EDANS fluorophore, eliminating FRET. EDANS fluorescence increases dramatically, making the reaction easy to follow continuously.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHow should I set up the assay?\u003c\/strong\u003e\u003cbr\u003eDissolve the substrate in your assay buffer, add protease, and monitor EDANS fluorescence (Ex ~330 nm, Em ~480 nm) over time. Include negative controls (substrate alone) and positive controls (pre-cleaved substrate).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHow is this different from stopped-end assays?\u003c\/strong\u003e\u003cbr\u003eFRET substrates allow real-time, kinetic measurements. No stopping reagent or additional steps are needed; you simply follow fluorescence over time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat is the stock substrate concentration?\u003c\/strong\u003e\u003cbr\u003eDissolve the 1 mg lyophilized peptide in a known volume of buffer. A 1 mM stock solution in 1 mL is common; exact concentration will depend on the peptide's molecular weight and your desired working concentration (typically 0.1–10 μM).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCan I use this substrate for high-throughput screening?\u003c\/strong\u003e\u003cbr\u003eYes. The assay is simple, rapid, and compatible with 96- and 384-well plate readers.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv style=\"margin-top:20px; font-weight:bold; color:#c8102e;\"\u003eThis product is for Research Use Only (RUO). It is not intended for diagnostic or therapeutic use in humans or animals.\u003c\/div\u003e\n\u003chr\u003e\n\u003ch4\u003eReferences\u003c\/h4\u003e\n\u003cul style=\"padding-left:0; margin:0; list-style:none;\"\u003e\n\u003cli style=\"display:flex; justify-content:space-between; align-items:flex-start; gap:12px; padding:8px 0; border-bottom:1px solid #eee;\"\u003e\n\u003cspan style=\"flex:1;\"\u003eEkici OD, Zhu J, Wah Chung IY, Paetzel M, Dalbey RE, Pei D. Profiling the substrate specificity of viral protease VP4 by a FRET-based peptide library approach. \u003cem\u003eBiochemistry.\u003c\/em\u003e 2009;48(24):5753-9.\u003c\/span\u003e\u003ca href=\"https:\/\/doi.org\/10.1021\/bi900461e\" target=\"_blank\" rel=\"noopener\" style=\"flex-shrink:0; margin-top:2px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/Reference.png?v=1775409336\" alt=\"Reference\" style=\"height:28px; width:auto;\"\u003e\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli style=\"display:flex; justify-content:space-between; align-items:flex-start; gap:12px; padding:8px 0; border-bottom:1px solid #eee;\"\u003e\n\u003cspan style=\"flex:1;\"\u003eGratz A, Götz C, Jose J. A FRET-based microplate assay for human protein kinase CK2, a target in neoplastic disease. \u003cem\u003eJ Enzyme Inhib Med Chem.\u003c\/em\u003e 2010;25(2):234-9.\u003c\/span\u003e\u003ca href=\"https:\/\/doi.org\/10.3109\/14756360903170038\" target=\"_blank\" rel=\"noopener\" style=\"flex-shrink:0; margin-top:2px;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/Reference.png?v=1775409336\" alt=\"Reference\" style=\"height:28px; width:auto;\"\u003e\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e","brand":"Molecular Depot","offers":[{"title":"Default Title","offer_id":52813556351274,"sku":"BTS-B2026695","price":935.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0896\/1579\/4474\/files\/B2026695_395d4d43-fc48-4c08-a7d3-df1da70bfbe8.png?v=1790897767","url":"https:\/\/bluetigerscientific.com\/products\/dabcyl-ktsavlqsgfrkm-glu-edans-fret-peptide-substrate-1","provider":"Blue Tiger Scientific","version":"1.0","type":"link"}