Protein Modification Reagents
Medchemexpress LLC Mal-PEG5-NHS ester | 1807537-42-3 | 99.0% | 10 MG
Mal-PEG5-NHS ester is an Alkyl/ether and PEG-based PROTAC linker. It is used in the synthesis of PROTACs, which are composed of two different ligands connected by a linker. One ligand is for an E3 ubiquitin ligase and the other is for the target protein. PROTACs function by exploiting the intracellular ubiquitin-proteasome system to selectively degrade target proteins.
- Alkyl/ether and PEG-based PROTAC linker
- Used in the synthesis of PROTACs
- Exploits ubiquitin-proteasome system
- Selectively degrades target proteins
Medchemexpress LLC DBCO-PEG6-NHS ester | 95.0% | 737.79 g·mol⁻¹ | C38H47N3O12 | 10 MG
DBCO-PEG6-NHS ester is a bifunctional click-chemistry reagent combining a dibenzocyclooctyne (DBCO) moiety and an N-hydroxysuccinimide (NHS) ester separated by a six-unit polyethylene glycol spacer. It is designed for amine-specific conjugation and copper-free strain-promoted alkyne-azide cycloaddition (SPAAC) with azide-functionalized partners, and is supplied as a light yellow liquid.
- Bifunctional linker with DBCO and NHS ester groups.
- PEG6 spacer improves solubility and reduces steric hindrance.
- Reacts with primary amines for stable covalent attachment.
- Performs copper-free SPAAC with azide groups for bioorthogonal labeling.
- Purity approximately 95% as provided in product documentation.
- Store protected from light and under inert atmosphere; recommended low-temperature storage for long-term stability.
Medchemexpress LLC Endo-BCN-PEG4-acid | 1881221-47-1 | 99.3% | 441.52 | C22H35NO8 | 25 MG
Endo-BCN-PEG4-acid is a cleavable four-unit PEG linker containing a bicyclononyne (BCN) group and a terminal carboxylic acid. It is used as a linker in antibody-drug conjugate (ADC) synthesis and as a reagent for strain-promoted alkyne-azide cycloaddition (SPAAC).
- Cleavable 4-unit polyethylene glycol (PEG) linker.
- Contains a BCN group for SPAAC click chemistry.
- Terminal carboxylic acid enables conjugation to amines or alcohols.
- High purity suitable for bioconjugation reactions.
- Colorless to light yellow liquid physical form.
- Long-term storage recommended at -20°C (pure form) or lower when in solution.
Medchemexpress LLC Dbco-PEG4-GGFG-Dxd | 98.4% | 1375.45 g/mol | C72H79FN10O17 | 50 MG
DBCO-PEG4-GGFG-Dxd is a DBCO-functionalized PEG4-linked GGFG peptide drug-linker conjugate incorporating Dxd, a topoisomerase I inhibitor, designed for antibody-drug conjugate (ADC) research and click-chemistry conjugation via its DBCO handle.
- Designed for ADC research and click-chemistry conjugation
- Contains Dxd, a topoisomerase I inhibitor
- Purity 98.4%
- Molecular weight 1375.45 g/mol
- Chemical formula C72H79FN10O17
- Appearance: solid, off-white to light yellow
- Storage: store protected from light; in solvent -80°C (6 months), -20°C (1 month)
- Available in small research quantities including 50 MG
Medchemexpress LLC Dbco-peg4-ggfg-dxd | 2694856-51-2 | 98.4% | 1375.45 | C72H79FN10O17 | 25 MG
Dbco-peg4-ggfg-dxd is a click-reactive drug-linker conjugate for research use in antibody-drug conjugate (ADC) development. It contains a DBCO group for strain-promoted alkyne-azide cycloaddition to enable conjugation to azide-functionalized antibodies or biomolecules, a PEG4 spacer for solubility, a GGFG peptide linker, and a DXd topoisomerase I inhibitor payload.
- Contains a DBCO click-reactive group for SPAAC conjugation.
- Includes a PEG4 spacer to improve solubility and flexibility.
- Features a GGFG peptide linker designed for cleavable release.
- Delivers the DXd topoisomerase I inhibitor payload for cytotoxic activity.
- Provided in small-milligram quantities suitable for research and ADC construction.
Medchemexpress LLC 3,6,9,12,15-Pentaoxaoctadec-17-ynoic acid | 1429934-37-1 | ≥97.0% | 290.31 | 25 MG
Propargyl-PEG4-CH2COOH is a PEG-based PROTAC linker and a click chemistry reagent. It contains an Alkyne group that can engage in copper-catalyzed azide-alkyne cycloaddition (CuAAc) reactions with Azide group-containing molecules. This linker is crucial for synthesizing PROTACs, which utilize the intracellular ubiquitin-proteasome system to selectively degrade target proteins.
- PEG-based PROTAC linker
- Used in the synthesis of PROTACs
- Functions as a click chemistry reagent
- Contains an alkyne group for CuAAc reactions
- Enables targeted protein degradation
Medchemexpress LLC Biotin-PEG4-TFP ester | 2985664-57-9 | 97.8% | C27H37F4N3O8S | 25 MG
Biotin-PEG4-TFP ester is a PEG-based PROTAC linker that can be used in the synthesis of PROTACs. PROTACs contain two different ligands connected by a linker, one for an E3 ubiquitin ligase and the other for the target protein. This linker exploits the intracellular ubiquitin-proteasome system to selectively degrade target proteins.
- PEG-based PROTAC linker
- Can be used in the synthesis of PROTACs
- Contains two different ligands connected by a linker
- Exploits the intracellular ubiquitin-proteasome system
- For research use only
Medchemexpress LLC NH2-C5-PEG4-N3-L-lysine-PEG3-N3 | 99.4% | 619.71 g/mol | C25H49N9O9 | 100 MG
A cleavable 7-unit polyethylene glycol (PEG) linker with an amino terminus and azide functionality used for antibody-drug conjugate (ADC) synthesis and bioconjugation workflows.
- Cleavable 7-unit PEG linker suitable for ADC synthesis.
- Contains amino (NH2) and azide (N3) functional groups for conjugation.
- High purity: 99.4%.
- Molecular weight: 619.71 g/mol.
- Soluble ≥ 100 mg/mL in water for aqueous conjugations.
- Available in multiple pack sizes, including 100 MG.
Medchemexpress LLC m-PEG5-succinimidyl carbonate | 1058691-00-1 | MFCD30828680 | 98.0% | 393.39 g/mol | C16H27NO10 | 100 MG
m-PEG5-succinimidyl carbonate is a non-cleavable, 5-unit polyethylene glycol (PEG) succinimidyl carbonate linker with an NHS-type carbonate reactive group for conjugation to primary amines. It is commonly used in synthesis of antibody-drug conjugates (ADCs), PROTAC linkers, and for PEGylation of amine-containing molecules. Typical specifications: purity 98.0%, molecular weight 393.39 g/mol, formula C16H27NO10, CAS 1058691-00-1.
- Provides an NHS-type carbonate reactive group for efficient amine conjugation.
- Non-cleavable 5-unit PEG spacer increases solubility and spacing between conjugated moieties.
- High purity (98.0%) suitable for research-grade conjugation chemistry.
- Available in small pack sizes to support synthetic workflows.
- Stable when stored frozen; follow solvent storage recommendations for solutions.
Medchemexpress LLC Sulfo-cyanine7-n3 | 97.6% | 763.95 g/mol | C38H47N6O7S2 | 10 MG
CY7-N3 (Sulfo-Cyanine7-N3) is a water-soluble near-infrared (NIR) azide dye designed for bioconjugation via click chemistry. The azide functional group enables copper-catalyzed azide-alkyne cycloaddition (CuAAC) and strain-promoted azide-alkyne cycloaddition (SPAAC), allowing efficient fluorescent labeling of biomolecules.
- Water-soluble NIR azide dye for click chemistry.
- Enables CuAAC and SPAAC conjugation reactions.
- Supplied as a green to dark green solid; also available as a DMSO solution.
- High purity (~97.6%) suitable for labeling applications.
- Stable when stored as a solid at 4°C and protected from light.
Bioassay Systems QuantiFluo™ Pepsin Inhibitor Assay Kit, For evaluation of drugs and screening of potential inhibitors to pepsin proteases.
PEPSIN (EC 3.4.23.1) is a digestive, serine protease that hydrolyzes dietary proteins in many eukaryotic and prokaryotic organisms. Pepsin predominantly cleaves peptide chains at the amino side of the aromatic phenylalanine, tryptophan, and tyrosine amino acids. BioAssay Systems’ QuantiFluo™ Pepsin Inhibitor Assay Kit uses a fluorescein isothiocyanate (FITC)-labeled synthetic substrate. The fluorescein label is highly quenched. Upon digestion by pepsin present in the sample, the substrate is cleaved into smaller peptides, which abolishes the quenching of the fluorescence label. The fluorescence or fluorescence polarization (FP) of the FITC-labeled fragments is measured at λex/em = 485/530 nm. Inhibition is determined by the decrease in fluorescence.
Medchemexpress LLC Bromo-PEG2-C2-azide | 530151-56-5 | MFCD25424115 | 98.7% | 238.08 g·mol⁻1 | C6H12BrN3O2 | 100 MG
Bromo-PEG2-C2-azide is a PEG-based bromo azide linker used as a non-cleavable linker in antibody-drug conjugate (ADC) synthesis and as a PROTAC linker. It contains an azide functional group for click chemistry and a bromoalkyl handle for further functionalization. Molecular formula C6H12BrN3O2; molecular weight 238.08 g·mol⁻1; purity ≥98.7%.
- Contains an azide group for copper-catalyzed and strain-promoted click reactions.
- Provides a bromoalkyl handle for alkylation or substitution reactions.
- Suitable as a non-cleavable linker for ADC synthesis and as a PROTAC linker.
- High purity for reliable synthetic performance.
- Available in small lab quantities for research use.