Protein Modification Reagents
Medchemexpress LLC N-Boc-PEG5-bromide | 1392499-32-9 | MFCD31536756 | 98.0% | 400.31 g/mol | C15H30BrNO6 | 500 MG
N-Boc-PEG5-bromide is a Boc-protected polyethylene glycol (PEG5) alkyl bromide linker used as a building block in medicinal chemistry for PROTAC and ADC linker synthesis. It provides an orthogonally protected amine and a terminal bromide for downstream coupling and substitution reactions. Supplied with high reported purity, it is intended for research use under appropriate laboratory conditions.
- Boc-protected amine for orthogonal deprotection.
- Five-unit PEG spacer provides flexibility and solubility.
- Terminal bromide enables nucleophilic substitution (SN2) chemistry.
- Reported purity approximately 98.0%.
- Suitable for assembly of PROTAC and ADC linkers.
- Recommended cold storage to preserve stability.
Medchemexpress LLC (S,R,S)-AHPC-PEG1-N3 | 2101200-09-1 | 98.8% | 557.67 g/mol | C26H35N7O5S | 50 MG
(S,R,S)-AHPC-PEG1-N3 is a VHL E3 ligase ligand-linker conjugate that incorporates an (S,R,S)-AHPC VHL ligand and a single-unit polyethylene glycol (PEG1) linker terminated with an azide. It is designed as a building block for PROTAC assembly and for click-chemistry conjugations (CuAAC), enabling attachment of functional moieties to VHL ligands.
- Contains an azide functional group for copper-catalyzed azide-alkyne cycloaddition (CuAAC).
- Single-unit PEG linker provides improved solubility and controlled spacing between ligands.
- High purity (>98.7%) and molecular weight 557.67 g/mol for consistent characterization.
- Soluble in DMSO (100 mg/mL); insoluble in water (<0.1 mg/mL).
- Stable as a powder when stored at -20°C (up to 3 years) or 4°C (up to 2 years).
Medchemexpress LLC Dspe-peg-biotin | 98.4% | 3400 Da | 25 MG
Biotinylated DSPE-PEG is an amphiphilic PEG-lipid conjugate (average molecular weight 3,400 Da) used to introduce biotin functionality into lipid assemblies. The DSPE lipid anchors the conjugate in bilayers while the PEG spacer presents biotin for high-affinity interactions with streptavidin/avidin. Supplied as a powder for research use, it is commonly applied in targeted delivery, surface functionalization, and assay development.
- Amphiphilic structure enables incorporation into liposomes and micelles.
- Biotin end-group for high-affinity binding to streptavidin/avidin.
- Average molecular weight 3.4 kDa for the PEG spacer.
- High reported purity (~98.4%).
- Available in small powder pack sizes for research use (for example, 25 mg).
- Recommended storage as powder at -20°C to maintain stability.
Medchemexpress LLC NHS-PEG1-SS-PEG1-NHS | 1688598-83-5 | 98.0% | 436.41 | 50 MG
NHS-PEG1-SS-PEG1-NHS is a reversible linker designed for conjugating biomacromolecules with active small molecules.
- Reversible linker
- Designed for conjugating biomacromolecules with active small molecules
- Suitable for use in proteins
- Suitable for use in liposomes
- Suitable for use in nanoparticles
Medchemexpress LLC Mal-PEG2-NHS ester | 1433997-01-3 | MFCD24539465 | 98.6% | 354.31 | C15H18N2O8 | 100 MG
Mal-PEG2-NHS ester is a bifunctional PEG linker designed for bioconjugation, combining a maleimide moiety for thiol coupling with an NHS ester for amine coupling to enable antibody-drug conjugate (ADC) and other conjugation chemistries.
- Non-cleavable dual-reactive linker enabling site-specific conjugation.
- Two-unit PEG spacer increases hydrophilicity and solubility.
- Maleimide group reacts selectively with thiol groups.
- NHS ester reacts with primary amines for stable amide bond formation.
- Available in small-scale quantities suitable for research use.
- Stored and handled to preserve stability: long-term frozen storage recommended.
![eMolecules bis-PEG2-endo-BCN | Broadpharm | 1476737-97-9 | MFCD19705423 | 500.636 | C28H40N2O6 | 97.000 | O=C(NCCOCCOCCNC(=O)OC[C@@H]1[C@@H]2CCC#CCC[C@H]12)OC[C@@H]1[C@@H]2CCC#CCC[C@H]12 | 50mg | 340377180](https://assets.fishersci.com/TFS-Assets/CCG/product-images/NC1737768.jpg-250.jpg)
eMolecules bis-PEG2-endo-BCN | Broadpharm | 1476737-97-9 | MFCD19705423 | 500.636 | C28H40N2O6 | 97.000 | O=C(NCCOCCOCCNC(=O)OC[C@@H]1[C@@H]2CCC#CCC[C@H]12)OC[C@@H]1[C@@H]2CCC#CCC[C@H]12 | 50mg | 340377180
bis-PEG2-endo-BCN | Broadpharm | 1476737-97-9 | MFCD19705423 | 500.636 | C28H40N2O6 | 97.000 | O=C(NCCOCCOCCNC(=O)OC[C@@H]1[C@@H]2CCC#CCC[C@H]12)OC[C@@H]1[C@@H]2CCC#CCC[C@H]12 | 50mg | 340377180
Medchemexpress LLC Aminooxy-PEG1-azide | 2100306-70-3 | MFCD30723212 | 98.0% | 146.15 g/mol | C4H10N4O2 | 5 MG
Aminooxy-PEG1-azide is a short bifunctional polyethylene glycol (PEG) linker bearing an aminooxy group and an azide group. It is designed for chemical biology and bioconjugation applications where orthogonal conjugation is required, enabling oxime ligation at one terminus and click chemistry at the other. Intended for research use only.
- Enables oxime ligation with aldehydes and ketones.
- Participates in copper-catalyzed and strain-promoted azide-alkyne cycloadditions.
- Provides a short PEG spacer to improve aqueous solubility and reduce steric hindrance.
- Suitable for linker construction in proteolysis targeting chimeric molecule (PROTAC) and bioconjugation workflows.
- Reported purity approximately 98%, compatible with research applications.
Medchemexpress LLC DOTA-PEG5-amine | 98.0% | 666.76 | 50 MG
DOTA-PEG5-amine is a PEG-based PROTAC linker designed for the synthesis of PROTACs. These molecules feature two ligands connected by a linker, one targeting an E3 ubiquitin ligase and the other a target protein. PROTACs utilize the intracellular ubiquitin-proteasome system to selectively degrade specific target proteins.
- PEG-based PROTAC linker
- Used in the synthesis of PROTACs
- Contains two different ligands connected by a linker
- Exploits the intracellular ubiquitin-proteasome system
- Selectively degrades target proteins
- For research use only
Cayman Chemical AzIdo-dPEG7-amIn 10mg
A heterobifunctional PEGylated linker; contains a reactive NH2 end group, as well as an azide functional group for use in click chemistry reactions; has been used as a linker in the synthesis of bivalent mTOR inhibitors
eMolecules 35164-96-6 | Tos-PEG21-Tos | Broadpharm | MFCD30458052 | 1207.440 | C54H94O25S2 | 95.000 | Cc1ccc(cc1)S(=O)(=O)OCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOS(=O)(=O)c1ccc(C)cc1 | 1g | 311074443
Tos-PEG21-Tos | Broadpharm | 35164-96-6 | MFCD30458052 | 1207.440 | C54H94O25S2 | 95.000 | Cc1ccc(cc1)S(=O)(=O)OCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOCCOS(=O)(=O)c1ccc(C)cc1 | 1g | 311074443
eMolecules 16-(Amine-PEG4-ethylcarbamoyl)pentadecanoic-t-butyl ester | Broadpharm |560.817 | C30H60N2O7 | 95.000 | CC(C)(C)OC(=O)CCCCCCCCCCCCCCC(=O)NCCOCCOCCOCCOCCN | 100mg | 795361477
16-(Amine-PEG4-ethylcarbamoyl)pentadecanoic-t-butyl ester | Broadpharm |560.817 | C30H60N2O7 | 95.000 | CC(C)(C)OC(=O)CCCCCCCCCCCCCCC(=O)NCCOCCOCCOCCOCCN | 100mg | 795361477
eMolecules 2055042-60-7 | N-(Boc-PEG3)-N-bis(PEG2-alcohol) | Broadpharm | MFCD30182039 | 556.694 | C25H52N2O11 | 97.000 | CC(C)(C)OC(=O)NCCOCCOCCOCCN(CCOCCOCCO)CCOCCOCCO | 500mg | 309208953
N-(Boc-PEG3)-N-bis(PEG2-alcohol) | Broadpharm | 2055042-60-7 | MFCD30182039 | 556.694 | C25H52N2O11 | 97.000 | CC(C)(C)OC(=O)NCCOCCOCCOCCN(CCOCCOCCO)CCOCCOCCO | 500mg | 309208953
Medchemexpress LLC Cy3-peg-biotin | 95.0% | 2000 (average) | 10 MG
Cy3-PEG-biotin is a polyethylene glycol conjugate bearing a Cy3 fluorescent dye and a biotin affinity tag; it is designed for fluorescence labeling and capture of biomolecules via biotin-streptavidin interactions for microscopy, flow cytometry, and nucleic acid or protein labeling.
- Provides Cy3 fluorescence for detection (max emission ≈ 562-570 nm).
- Biotin tag enables high-affinity capture by streptavidin/avidin.
- PEG spacer (average MW 2000) improves solubility and reduces steric hindrance.
- Available in small laboratory quantities suitable for labeling workflows.
Medchemexpress LLC PEG5-Tos | 155130-15-7 | 96.9% | 392.46 | 1 G
PEG5-Tos is a PEG-based PROTAC linker that can be used in the synthesis of PROTACs. PROTACs (Proteolysis Targeting Chimeras) consist of two different ligands connected by a linker; one ligand targets an E3 ubiquitin ligase, and the other targets the protein of interest. PROTACs utilize the intracellular ubiquitin-proteasome system to selectively degrade target proteins.
- PEG-based PROTAC linker
- Used in the synthesis of PROTACs
- For research use only
Medchemexpress LLC Amino-PEG4-C2-SH hydrochloride | 95.0% | 289.82 g/mol | C10H24ClNO4S | 5 MG
Amino-PEG4-C2-SH hydrochloride is a PEG-based PROTAC linker supplied as the hydrochloride salt for research use. The molecule features a PEG4 spacer with a terminal amino group and a terminal thiol, enabling orthogonal conjugation strategies in bifunctional molecule synthesis. It is provided with characterized purity and molecular weight suitable for medicinal chemistry and linker development applications.
- Hydrochloride salt for improved handling and stability.
- Terminal amino and thiol groups for orthogonal conjugation.
- PEG4 spacer provides flexibility and aqueous solubility.
- Characterized purity for research-grade synthesis.
- Intended for use in PROTAC and linker chemistry.