Protein Modification Reagents
![Medchemexpress LLC L-ornithinamide, n-[3-[2-[2-(2-azidoethoxy)ethoxy]ethoxy]-1-oxopropyl]-l-valyl-... | 2055047-18-0 | MFCD30527416 | 99.1% | 773.79 g/mol | C34H47N9O12 | 50 MG](https://assets.fishersci.com/TFS-Assets/CCG/product-images/5000204155.png-250.jpg)
Medchemexpress LLC L-ornithinamide, n-[3-[2-[2-(2-azidoethoxy)ethoxy]ethoxy]-1-oxopropyl]-l-valyl-... | 2055047-18-0 | MFCD30527416 | 99.1% | 773.79 g/mol | C34H47N9O12 | 50 MG
Cleavable PEG linker containing an azide functional group designed for use in antibody-drug conjugate and PROTAC synthesis. The molecule features a PEG3 spacer, a Val-Cit dipeptide cleavable by proteases, and a para-aminobenzyl (PAB) activated ester for payload attachment. It is compatible with copper-catalyzed and strain-promoted azide-alkyne cycloaddition reactions.
- Cleavable val-cit dipeptide enables enzymatic payload release
- Azide functional group supports CuAAC and SPAAC click chemistries
- Peg3 spacer improves solubility and flexibility in conjugates
- PAB-PNP moiety provides an activated ester for payload coupling
- High purity suitable for synthetic bioconjugation workflows
Medchemexpress LLC Mal-PEG2-VCP-eribulin | 2130869-18-8 | MFCD32068377 | 99.8% | 1374.57 | C70H99N7O21 | 10 MG
Mal-PEG2-VCP-eribulin is a drug-linker conjugate composed of an ADC linker (Mal-PEG2-VCP) covalently attached to eribulin. It is supplied as a solid for research use in the development of antibody-drug conjugates and related preclinical studies.
- Consists of an ADC linker conjugated to eribulin.
- CAS number 2130869-18-8.
- Molecular weight 1374.57.
- Chemical formula C70H99N7O21.
- Purity 99.8%.
- Supplied as a 10 MG solid; other pack sizes available on request.
- Store at -20°C, protect from light, under inert atmosphere; in solvent store at -80°C (6 months) or -20°C (1 month).
Medchemexpress LLC NH2-C5-PEG4-N3-L-lysine-PEG3-N3 | 99.4% | 619.71 g/mol | C25H49N9O9 | 1 MG
NH2-C5-PEG4-N3-L-lysine-PEG3-N3 is a cleavable 7-unit polyethylene glycol (PEG) linker bearing an azide functionality for use in click chemistry and antibody-drug conjugate (ADC) synthesis. It enables copper-catalyzed azide-alkyne cycloaddition (CuAAC) and strain-promoted azide-alkyne cycloaddition (SPAAC) bioconjugation workflows, and is supplied as a highly pure, water-soluble reagent.
- Cleavable 7-unit PEG linker
- Contains an azide group for click chemistry
- Suitable for CuAAC and SPAAC bioconjugation
- Soluble in water at ≥ 100 mg/mL
- High purity: 99.42%
- Available in small-scale quantities for research use
Medchemexpress LLC DBCO-PEG5-NHS ester | 2144395-59-3 | MFCD22380747 | 95.0% | 693.74 g/mol | C36H43N3O11 | 5 MG
DBCO-PEG5-NHS ester is a DBCO-functionalized PEG5 N-hydroxysuccinimide (NHS) ester used for copper-free click chemistry and amine-directed coupling in bioconjugation. It combines a strained dibenzocyclooctyne (DBCO) for strain-promoted alkyne-azide cycloaddition (SPAAC) with an NHS ester reactive toward primary amines, making it suitable as an ADC or PROTAC linker and in general lab bioconjugation workflows.
- Contains a DBCO strained alkyne for copper-free click chemistry.
- Contains an NHS ester for efficient coupling to primary amines.
- PEG5 spacer provides hydrophilicity and flexible linkage.
- Suitable for ADC and PROTAC linker construction and general bioconjugation.
- Supplied as a solid with reported purity of approximately 95% and molecular weight ~693.7 g/mol.
![Medchemexpress LLC 4,7,10,13-tetraoxahexadecanediamide, N1,N16-bis[3-(11,12-didehydrodibenz[b,f]azocin-5(6H)-yl)-3-oxopropyl] | 2182601-68-7 | 97.4% | 810.93 | C48H50N4O8 | 25 MG](https://assets.fishersci.com/TFS-Assets/CCG/product-images/5000204012.png-250.jpg)
Medchemexpress LLC 4,7,10,13-tetraoxahexadecanediamide, N1,N16-bis[3-(11,12-didehydrodibenz[b,f]azocin-5(6H)-yl)-3-oxopropyl] | 2182601-68-7 | 97.4% | 810.93 | C48H50N4O8 | 25 MG
DBCO-PEG4-DBCO is a PEG-based bifunctional dibenzocyclooctyne (DBCO) linker that enables strain-promoted alkyne-azide cycloaddition (SPAAC) for copper-free click chemistry. It contains two DBCO groups connected by a PEG4 spacer, is supplied as a white-to-yellow solid, and is used as a cleavable linker in ADC and PROTAC synthesis.
- enables copper-free SPAAC (strain-promoted alkyne-azide cycloaddition)
- contains two DBCO reactive groups connected by a PEG4 spacer
- high purity: 97.4% (HPLC)
- molecular weight: 810.93 g/mol
- supplied as a white-to-yellow solid with recommended sealed, moisture-free storage
Medchemexpress LLC Biotin-PEG2-acid | 1365655-89-5 | MFCD22056305 | ≥97.0% | 403.49 g·mol⁻¹ | C17H29N3O6S | 250 MG
Biotin-PEG2-acid is a biotinylated polyethylene glycol linker with a terminal carboxylic acid, used as a non-cleavable ADC and PROTAC linker for bioconjugation, affinity labeling, and linker synthesis. It is supplied in small laboratory pack sizes for conjugation workflows.
- Biotinylated PEG linker with a terminal carboxylic acid for conjugation.
- Non-cleavable two-unit PEG spacer suited for ADC and PROTAC syntheses.
- High purity (≥97.0%) for reliable conjugation performance.
- Molecular weight 403.49 g·mol⁻¹; formula C17H29N3O6S.
- Available in small-scale quantities such as 250 MG.
- Store protected from light under argon at -20°C; in solvent store at -80°C for long-term.
Medchemexpress LLC HOOC-PEG-SH MW 5000 5mg
HOOC-PEG-SH (MW 5000) (HOOC-PEG-Thiol (MW 5000)) is a reactive thiol PEG derivative with a terminal carboxyl group The carboxyl group can react with amine or hydroxyl groups to form a stable amide bond or an unstable ester bond The PEG linkage between the thiol and carboxyl groups has good water solubility flexible linker distance and higher stability[1]
Medchemexpress LLC Azide-PEG4-VC-PAB-doxorubicin | 99.6% | 1222.25 g·mol⁻1 | C57H75N9O21 | 50 MG
Azide-PEG4-VC-PAB-doxorubicin is an antibody-drug conjugate (ADC) agent-linker conjugate that couples the cytotoxic anthracycline doxorubicin to an azide-terminated PEG4-VC-PAB linker for use in bioconjugation and ADC assembly. It is designed for click chemistry conjugation (CuAAC and SPAAC) to alkyne- or DBCO/BCN-containing partners and is supplied as a solid for research use.
Medchemexpress LLC Mal-PEG4-Val-Cit-PAB | 1949793-41-2 | 98.9% | 777.86 | C36H55N7O12 | 5 MG
Mal-PEG4-Val-Cit-PAB is a cleavable antibody-drug conjugate (ADC) linker that contains a maleimide reactive group, a four-unit polyethylene glycol (PEG4) spacer, a valine-citrulline (Val-Cit) dipeptide, and a para-aminobenzyl (PAB) self-immolative spacer. It is used in the synthesis of ADCs to enable protease-triggered release of cytotoxic payloads.
- Cleavable linker for protease-triggered payload release.
- Contains maleimide functional group for thiol conjugation.
- PEG4 spacer to improve solubility and reduce aggregation.
- Val-Cit-PAB motif enables self-immolation and controlled payload release.
- High purity (98.9%) and characterized molecular weight 777.86.
- Available in a 5 mg vial for research use.
Medchemexpress LLC Mal-PEG4-Val-Cit-PAB | 1949793-41-2 | 98.9% | 777.86 | C36H55N7O12 | 10 MG
Mal-PEG4-Val-Cit-PAB is a cleavable antibody-drug conjugate (ADC) linker containing a terminal maleimide group for thiol conjugation. The construct includes a PEG4 spacer and a valine-citrulline-PAB protease-cleavable sequence to enable enzymatic payload release after internalization.
- Cleavable valine-citrulline-PAB sequence for enzyme-triggered release.
- Maleimide terminal for efficient thiol conjugation to antibodies.
- PEG4 spacer increases solubility and reduces steric hindrance.
- High supplied purity for consistent conjugation performance.
- Soluble in DMSO; recommended storage sealed and away from moisture.
Medchemexpress LLC Benzyl-PEG5-Ots 500mg
Benzyl-PEG5-Ots is a PEG-based PROTAC linker can be used in the synthesis of PROTACs
Medchemexpress LLC Dbco-nhco-peg4-nh-boc | 1255942-12-1 | MFCD30730371 | >96.0% | 623.74 g/mol | C34H45N3O8 | 25 MG
Dbco-nhco-peg4-nh-boc is a DBCO-functionalized PEG4 linker used for copper-free click chemistry (SPAAC) in bioconjugation, antibody-drug conjugate assembly, and PROTAC synthesis.
- Enables copper-free click chemistry with azide-functionalized molecules.
- Suitable for antibody-drug conjugate and PROTAC linker synthesis.
- Boc-protected amine facilitates selective deprotection and further functionalization.
- Available in small laboratory quantities for research use.
- Stable when stored at recommended temperatures.