Protein Modification Reagents
Medchemexpress LLC (S,R,S)-AHPC-PEG4-NH2 hydrochloride | 2064292-52-8 | 98.2% | 700.29 g/mol | C32H50ClN5O8S | 50 MG
(S,R,S)-AHPC-PEG4-NH2 hydrochloride is a synthesized E3 ligase VHL ligand-linker conjugate used as a PROTAC building block. It combines an (S,R,S)-configured AHPC VHL ligand with a four-unit PEG linker terminating in a primary amine, providing a conjugation handle for assembling bifunctional degraders.
- VHL ligand core for recruiting the VHL E3 ligase.
- Four-unit PEG linker imparts flexibility and improves solubility.
- Terminal primary amine enables straightforward conjugation to warheads or linkers.
- High purity suitable for research synthesis (≈98.2%).
- Water solubility up to 50 mg/mL (ultrasonic may be required) for formulation convenience.
- Supplied as a hydrochloride salt to aid stability and handling.
- Intended for use as a PROTAC intermediate in targeted protein degradation research.
Medchemexpress LLC Carboxy-PEG4-phosphonic acid | 1623791-69-4 | 96.0% | C11H23O9P | 100 MG
Carboxy-PEG4-phosphonic acid is a PEG-based PROTAC linker used in the synthesis of PROTACs. PROTACs are compounds with two distinct ligands connected by a linker, one targeting an E3 ubiquitin ligase and the other the protein of interest. This mechanism allows PROTACs to leverage the intracellular ubiquitin-proteasome system for selective degradation of target proteins.
- PEG-based PROTAC linker
- Used in the synthesis of PROTACs
- Enables selective degradation of target proteins
Medchemexpress LLC Biotin-PEG2-C2-iodoacetamide | 292843-75-5 | 98.23% | C18H31IN4O5S | 50 MG
Biotin-PEG2-C2-iodoacetamide 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 is a ligand for an E3 ubiquitin ligase and the other is for the target protein.
- PROTACs exploit the intracellular ubiquitin-proteasome system to selectively degrade target proteins.
Medchemexpress LLC Biotin-PEG4-dialkoxydiphenylsilane-picolyl azide | 2599839-59-3 | 95.0% | C47H67N9O10SSi | 25 MG
Biotin-PEG4-dialkoxydiphenylsilane-picolyl azide is a clickable, acid-cleavable biotin-picolyl azide. It functions as an enrichment handle for cell surface glycoproteins, facilitating protein labeling.
- Clickable, acid-cleavable biotin-picolyl azide
- Functions as an enrichment handle for cell surface glycoproteins
- Suitable for protein labeling
- Azide group enables copper-catalyzed azide-alkyne cycloaddition (CuAAc)
- Participates in ring strain-promoted alkyne-azide cycloaddition (SPAAC)
Medchemexpress LLC Dbco-PEG4-VA-PBD | 2241644-09-5 | MFCD00012576 | 99.7% | 1430.60 g·mol⁻1 | C80H87N9O16 | 5 MG
DBCO-PEG4-VA-PBD is a click chemistry reagent and drug-linker conjugate used to attach pyrrolobenzodiazepine (PBD) payloads to biomolecules via strain-promoted alkyne-azide cycloaddition (SPAAC). It contains a DBCO moiety, a PEG4 spacer, and a valine-alanine cleavable linker designed for antibody-drug conjugate (ADC) assembly.
- Functions as a SPAAC-compatible click chemistry reagent.
- Contains a PEG4 spacer and a valine-alanine cleavable linker.
- Includes a pyrrolobenzodiazepine (PBD) cytotoxic payload.
- High purity suitable for research applications.
- Contains a single defined molecular formula and molecular weight for characterization.
- Intended for research use in bioconjugation and ADC development.
Medchemexpress LLC Methyltetrazine-PEG4-amine hydrochloride | 2245150-18-7 | MFCD31813569 | 99.5% | C17H26ClN5O4 | 10MG
Methyltetrazine-PEG4-amine hydrochloride is a PEG4-linked primary amine functionalized with a methyltetrazine group, provided as the hydrochloride salt. It functions as a click-chemistry reagent that undergoes rapid inverse-electron-demand Diels-Alder (iEDDA) reactions with trans-cyclooctene (TCO) partners, enabling bioorthogonal labeling and site-specific conjugation in bioconjugation workflows. Supplied as a solid (purplish red to red) with high purity; store sealed at 4°C.
- Enables rapid iEDDA click reactions with TCO partners.
- PEG4 spacer improves solubility and flexibility.
- Terminal primary amine allows straightforward conjugation chemistry.
- Hydrochloride salt form enhances stability for storage.
- High purity (~99.5%) suitable for labeling and conjugation.
- Solid form, easy to handle and store at 4°C.
Medchemexpress LLC Mal-amido-PEG2-NHS ester | 955094-26-5 | MFCD11041137 | 99.3% | 425.39 g/mol | C18H23N3O9 | 50 MG
Mal-amido-PEG2-NHS ester is a noncleavable ADC linker containing a maleimide reactive group and an N-hydroxysuccinimide (NHS) ester. The NHS ester labels primary amines (-NH2) to form stable amide bonds, while the maleimide enables thiol conjugation for bioconjugation and linker chemistry applications.
- Noncleavable ADC linker with maleimide and NHS ester.
- Reacts with primary amines to form stable amide bonds.
- Enables thiol conjugation via the maleimide functionality.
- High purity suitable for research-grade bioconjugation.
- Supplied as a solid for easy handling and storage.
eMolecules S-acetyl-PEG3-alcohol | 153870-20-3 | MFCD22574787 | 1g
Broadpharm | S-acetyl-PEG3-alcohol | 1g | 137364442 | BP-20945 | 98.000 | 153870-20-3 | MFCD22574787 | 208.270 | C8H16O4S
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Medchemexpress LLC Tos-PEG4-t-butyl ester | 217817-01-1 | 100 MG
Tos-PEG4-t-butyl ester is a PROTAC linker characterized by its PEG composition. It is utilized in the synthesis of various PROTACs, including BI-3663. BI-3663 is a highly selective PTK2/FAK PROTAC that employs cereblon ligands to facilitate E3 ligase hijacking for PTK2 degradation, demonstrating an IC50 of 18 nM for PTK2 inhibition.
- PROTAC linker
- Used in the synthesis of PROTACs
- Specific application in creating highly selective PTK2/FAK PROTACs
- Inhibits PTK2 with an IC50 of 18 nM when used in PROTACs
eMolecules Cy5-PEG4-acid | BroadpharmMFCD28142461 | 766.420 | C43H60ClN3O7 | 96.000 | [Cl-].CN1\C(=C\C=C\C=C\C2=[N+](CCCCCC(=O)NCCOCCOCCOCCOCCC(O)=O)c3ccccc3C2(C)C)C(C)(C)c2ccccc12 | 10mg | 263744692
Cy5-PEG4-acid | BroadpharmMFCD28142461 | 766.420 | C43H60ClN3O7 | 96.000 | [Cl-].CN1\C(=C\C=C\C=C\C2=[N+](CCCCCC(=O)NCCOCCOCCOCCOCCC(O)=O)c3ccccc3C2(C)C)C(C)(C)c2ccccc12 | 10mg | 263744692
Cayman Chemical Boc-NH-PEG3-CH2CoH 25mg
A building block; has been used as a linker in the synthesis of PROTACs targeting MEK; has been used as a spacer in the synthesis of radiolabeled probes for dual labeling of tumor integrin αVβ3 and GRPR in tumor tissue in vivo
Medchemexpress LLC Mal-PEG2-Val-Cit-PABA | 1662687-83-3 | 98.9% | 590.63 | C27H38N6O9 | 5 MG
Mal-PEG2-Val-Cit-PABA is a cleavable antibody-drug conjugate (ADC) linker designed for synthesis of ADCs. It features a maleimide reactive handle, a PEG2 spacer for improved hydrophilicity, and a Val-Cit-PABA cleavage motif that enables protease-mediated release of payloads in target cells.
- Cleavable Val-Cit-PABA motif for protease-triggered payload release.
- Maleimide functional group for thiol-selective conjugation to antibodies.
- PEG2 spacer increases hydrophilicity and may reduce aggregation.
- High chemical purity suitable for research and ADC synthesis.
- Stable when stored as powder at -20°C; follow recommended solvent storage conditions.
Medchemexpress LLC BCN-endo-PEG2-maleimide | 2675364-08-4 | 98.1% | 475.53 | C24H33N3O7 | 25 MG
A bifunctional linker reagent containing an endo-bicyclononyne reactive group and a maleimide separated by a PEG2 spacer, designed for strain-promoted azide-alkyne cycloaddition and thiol conjugation in bioconjugation and drug-delivery workflows.
- Contains endo-bicyclononyne and maleimide reactive groups.
- Peg2 spacer provides flexibility and solubility.
- Enables catalyst-free strain-promoted azide-alkyne cycloaddition (SPAAC) with azides.
- Compatible with maleimide-mediated thiol conjugation.
- High purity and defined molecular weight for reproducible conjugation.
Medchemexpress LLC Amino-PEG6-amido-bis-PEG5-N3 | 1147.31 g/mol | C48H94N10O21 | 100 MG
Amino-PEG6-amido-bis-PEG5-N3 is a cleavable PEG-based linker designed for bioconjugation and click chemistry applications. It contains an azide functional group and an amino terminus, providing an azide handle suitable for copper-catalyzed azide-alkyne cycloaddition and formation of antibody-drug conjugates or other bioconjugates.
- Cleavable 11-unit PEG linker for ADC and bioconjugate synthesis.
- Azide functional group compatible with CuAAC (click chemistry).
- Molecular weight 1,147.31 g/mol; formula C48H94N10O21.
- Appearance oil; colorless to light yellow.
- Solubility in DMSO ≥ 100 mg/mL.
- Storage sealed, away from moisture and light; recommended -20°C (in solvent: -80°C, 6 months; -20°C, 1 month).
- Available in multiple pack sizes including 100 mg.
eMolecules 557756-85-1 | Fmoc-NH-PEG4-CH2CH2COOH | Ambeed | MFCD06656472 | 487.549 | C26H33NO8 | 98.000 | OC(=O)CCOCCOCCOCCOCCNC(=O)OCC1c2ccccc2-c2ccccc12 | 100mg | 490490352
Fmoc-NH-PEG4-CH2CH2COOH | Ambeed | 557756-85-1 | MFCD06656472 | 487.549 | C26H33NO8 | 98.000 | OC(=O)CCOCCOCCOCCOCCNC(=O)OCC1c2ccccc2-c2ccccc12 | 100mg | 490490352