Activated PEGs for Thiol PEGylation

PEGylationJenKem Technology provides high quality activated polyethylene glycol derivatives (PEGs) with high purity and low polydispersity for Thiol PEGylation or Sulfhydyl PEGylation.

Methoxy PEG Maleimide is selective for thiol groups on cystein side chains. Y-shape PEG Maleimide is more selective, due to its sterically bulky structure. The bulky structure of JenKem Technology’s proprietary Y-shape branched PEG derivatives, consisting of two linear methoxy PEG chains attached to a central core with an active maleimide group, may help to reduce the number of attachment sites to a protein molecule.Methoxy PEG Vinylsulfone is a sulfhydryl reactive PEG that reacts at high pH. Methoxy PEG Thiol polydisperse or monodisperse PEGs are thiol reactive towards the SH groups on cysteine side chains under mild reaction conditions. PolyLactide PEG Maleimide (PLA PEG Maleimide) is a biodegradable thiol reactive PEG co-polymer usually employed for controlled drug release.

Activated PEG products for thiol PEGylation with molecular weights, branching, and functional groups not listed in our online catalog may be available by custom synthesis. Please inquire at about pricing and availability of custom PEGs for thiol PEGylation. For global distribution, please visit link. To order directly from JenKem Technology:

Y-shaped  PEG Maleimide
Y-PEG-MAL ≥ 95% Y-shape PEG Maleimide reacts with thiol groups at pH 5.0-6.5. JenKem proprietary Y-shape PEGs are more selective, due to their sterically bulky structure.[1]
U-shaped Branched PEG Maleimide
MPEG2-LYS-MAL ≥ 95% MPEG2 Lysine Maleimide  with superior quality; reacts with thiol groups on cystein side chains, such as thiols on the active ingredient of Certolizumab- pegol (Cimzia®).
Linear Methoxy Maleimide PEGs
M-PEG-MAL ≥ 95% Methoxy PEG Maleimide from JenKem Technology is a thiol reactive PEG derivative selective for thiol groups on cystein side chains.Methoxy PEG Maleimide undergoes thiol PEGylation reactions with thiol-containing molecules at pH 5.0-6.5. [2-4], [15-20].
Linear Methoxy Vinylsulfone PEGs
M-PEG-VS ≥ 90% Methoxy PEG Vinylsulfone are high quality products for sulfhydryl PEGylation. Methoxy Vinylsulfone PEG products are special thiol PEGylation PEGs that react at high pH. [5]
Linear Methoxy Thiol PEGs
M-PEG-SH ≥ 95% Methoxy PEG Thiol is a high quality activated PEG product for thiol pegylation. Methoxy PEG Thiol PEGylates the thiol groups on cysteine side chains under mild reaction conditions.[6-9], [21-25].
M-PEG5-SHM-PEG6-SH ≥ 90% Methoxy PEG5 Thiol and Methoxy PEG6 Thiol monodisperse Methoxy PEG Thiol products for thiol PEGylation in mild conditions. [10]
Biodegradable PolyLactide Linear PEG Maleimide Co-Polymer (PLA PEG Maleimide)
MAL-PEG5000-b-PLA20K ≥90% MAL-PEG5000-b-PLA20K, Maleimide Polyethylene Glycol Polylactide block copolymer, PEG MW 5000, PLA MW 20000, Substitution (Maleimide) ≥ 70%. Biodegradable PEG for controlled release applications.
MAL-PEG2000-b-PLA2000 ≥90% MAL-PEG2000-b-PLA2000, Maleimide Polyethylene Glycol Polylactide block copolymer, PEG MW 2000, PLA MW 2000, Substitution (Maleimide) ≥ 70%. Biodegradable PEG for controlled release applications.
Linear Methoxy Acrylate PEGs
M-PEG-ACLT ≥ 90% Methoxy PEG Acrylate are special high quality thiol reactive PEGs. [27]
Homobifunctional Activated PEG for Thiol PEGylation
MAL-PEG-MAL > 90% Maleimide PEG Maleimide. Selective crosslinker for thiol groups on cystein side chains. [11]
HS-PEG-SH ≥ 95% Thiol PEG Thiol. Thiol reactive PEG crosslinker, reacts with HS groups on cysteine side chains under mild reaction conditions. [12], [26].
VS-PEG-VS > 90% Vinylsulfone PEG Vinylsulfone. Sulfhydryl reactive homobifunctional PEG crosslinker [13, 14].
TSO-PEG-TSO > 90% Tosylate PEG Tosylate. Tosylate PEG Tosylate (diTosylate PEG, diToluenesulfonyl PEG, or PEG (Tosylate)2) is employed for amine and thiol pegylation.
Monodisperse Heterobifunctional PEGs Functionalized with Thiol
Monodisperse Thiol PEG Propionic Acid
Heterobifunctional PEGs Functionalized with Thiol Reactive Groups
Heterobifunctional Thiol Reactive PEGs
Multiarm Homofunctional PEGs Functionalized with Thiol Reactive Groups
Multiarm Homofunctional PEGs
Multiarm Heterobifunctional PEGs Functionalized with Thiol Reactive Groups
Multiarm Heterobifunctional PEGs


1. Li, H., et al., Dual MMP7-Proximity-Activated and Folate Receptor-Targeted Nanoparticles for siRNA Delivery, Biomacromolecules 2015, 16 (1), p: 192–201.

2. Chan, L.J., et al., Conjugation of 10 kDa linear PEG onto trastuzumab Fab’is sufficient to significantly enhance lymphatic exposure while preserving in vitro biological activity, Molecular Pharmaceutics. 2016.

3. Sawhney, P., et al., PEGylation of Truncated Streptokinase Leads to Formulation of a Useful Drug with Ameliorated Attributes. PloS one. 2016;11(5):e0155831.

4. Turaga, R.C., et al., Rational design of a protein that binds integrin [alpha] v [beta] 3 outside the ligand binding site. Nature communications. 2016;7.

5. Mahou, R., et al., Injectable and inherently vascularizing semi-interpenetrating polymer network for delivering cells to the subcutaneous space, Biomaterials, 2017.

6. Kampert, T., et al., Phenotypically Screened Carbon Nanoparticles for Enhanced Combinatorial Therapy in Triple Negative Breast Cancer, Cellular and Molecular Bioengineering, 2017:1-6.

7. Billingsley, M.M., et al., Antibody-nanoparticle conjugates to enhance the sensitivity of ELISA-based detection methods, PloS one, 2017, 12(5):e0177592.

8. Li, S.S., et al., Revealing chemical processes and kinetics of drug action within single living cells via plasmonic Raman probes, Scientific Reports, 2017, 7.

9. Srivastava, I., et al., Surface chemistry of carbon nanoparticles functionally select their uptake in various stages of cancer cells, Nano Research, 2017:1-6.

10. Mei, L., et al., Increased tumor targeted delivery using a multistage liposome system functionalized with RGD, TAT and cleavable PEG. International Journal of Pharmaceutics, 2014. 468(1–2): p. 26-38.

11. Azam, A., et al., Type III secretion as a generalizable strategy for the production of full-length biopolymer-forming proteins, Biotechnol. Bioeng. 2015, doi:10.1002/bit.25656.

12.  Kozai, T.D.Y, et al., Two-photon imaging of chronically implanted neural electrodes: Sealing methods and new insights, Journal of Neuroscience Methods, 2016, Volume 258, Pages 46-55.

13. Heffernan, J.M., et al., Bioengineered Scaffolds for 3D Analysis of Glioblastoma Proliferation and Invasion, Annals of Biomedical Engineering,, Volume 43, Issue 8, pp 1965-1977.

14. Addington, C.P., et al., Enhancing neural stem cell response to SDF-1α gradients through hyaluronic acid-laminin hydrogels, Biomaterials, 2015, Volume 72, Pages 11-19.

15. Chang, X., et al., Conjugation of PEG-hexadecane markedly increases the immunogenicity of pneumococcal polysaccharide conjugate vaccine, Vaccine, 2017, 35(13):1698-704.
Wan, X., et al., Effect of protein immunogenicity and PEG size and branching on the anti-PEG immune response to PEGylated proteins, Process Biochemistry, 2017, 52:183-91.

16. Wang, Y., et al., A PEGylated bovine hemoglobin as a potent hemoglobin‐based oxygen carrier, Biotechnology progress, 2017, 33(1):252-60.

17. Wang, J., et al., Size- and surface chemistry-dependent pharmacokinetics and tumor accumulation of engineered gold nanoparticles after intravenous administration, Metallomics, 2015, 7, 516-524.

18. Ren, H., et al., Peptide GE11–Polyethylene Glycol–Polyethylenimine for targeted gene delivery in laryngeal cancer, Medical Oncology, 2015, 32:185.

19. Zhang, T., et al., Moderate PEGylation of the carrier protein improves the polysaccharide-specific immunogenicity of meningococcal group A polysaccharide conjugate vaccine, Vaccine, 2015, Volume 33, Issue 28, Pages 3208-3214.

20. Hadadian, S., et al., Stability and biological activity evaluations of PEGylated human basic fibroblast growth factor, Advanced biomedical research, 2015;4.

21. Li, H., et al., Combination of active targeting, enzyme-triggered release and fluorescent dye into gold nanoclusters for endomicroscopy-guided photothermal/photodynamic therapy to pancreatic ductal adenocarcinoma, Biomaterials, 2017.

22. Liu, D., et al., A Fully Integrated Distance Readout ELISA-Chip for Point-of-Care Testing with Sample-in-Answer-out Capability, Biosensors and Bioelectronics, 2017.

23. Yue, Q., et al., An EGFRvIII targeted dual-modal gold nanoprobe for imaging-guided brain tumor surgery, Nanoscale, 2017.

24. Tian, L., et al., Plasmonic Nanogels for Unclonable Optical Tagging, ACS Applied Materials & Interfaces, 2016, 8 (6), 4031-4041.

25. Hu, W., et al., Redox and pH dual responsive poly(amidoamine) dendrimer-poly(ethylene glycol) conjugates for intracellular delivery of doxorubicin, Acta Biomaterialia, 2016, 36, p: 241-253.

26. Sridhar, B. V., et al., Development of a Cellularly Degradable PEG Hydrogel to Promote Articular Cartilage Extracellular Matrix Deposition. Advanced Healthcare Materials, 2015, 4: 702–713.

27. Hu, Y., et al., Facile Construction of Mitochondria-Targeting Nanoparticles for Enhanced Phototherapeutic Effects, Biomaterials Science, 2017.

Founded in 2001 by recognized experts in PEG synthesis and PEGylation, JenKem Technology specializes exclusively in the development and manufacturing of high quality polyethylene glycol (PEG) products and derivatives, and related custom synthesis and PEGylation services. JenKem Technology is ISO 9001 and ISO 13485 certified, and adheres to ICH Q7A guidelines for GMP manufacture. The production of JenKem® PEGs is back-integrated to on-site manufacturing from ethylene oxide, enabling facile traceability for GMP regulated customers. JenKem Technology caters to the PEGylation needs of the pharmaceutical, biotechnology, medical device and diagnostics, and emerging chemical specialty markets, from laboratory scale through large commercial scale.

Continue Reading