Description

Hydroxy-dPEG®4-TFP ester, product number QBD-11341, is a short (16 atoms, 17.9 Å), hydroxy-terminated, single molecular weight, discrete polyethylene glycol (dPEG®) compound functionalized with a 2,3,5,6-tetrafluorophenyl (TFP) ester for conjugation to primary and secondary amines. This product can be used for modification of amine-functionalized surfaces (e.g., silica, glass), modification of proteins and peptides at accessible amine sites on the molecules, the construction of discrete PEG dendrimers, and many other applications. The free hydroxy end of the dPEG® spacer can be functionalized for further reactions or left unmodified to increase hydrophilicity or modify the charge of conjugate molecules and surfaces.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). Specifically see pp. 726-729 in his Chapter 18 on discrete PEG compounds for pegylation applications.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See chapter 18, Discrete PEG Reagents, pp.787-821, for a full overview of the dPEG® products.

Description

m-dPEG®4-Lipoamide, product number QBD-10799, is a short (21 atoms), amphiphilic, methyl-terminated, monodisperse PEG product functionalized with lipoic acid and designed to modify metal surfaces such as gold or silver. The primary application of this product is the stable passivation of metal surfaces through the use of lipoic acid, which forms two dative bonds with gold or silver, conjugated to a short, monodispersed PEG spacer. Because the terminal dithiolane unit forms two dative bonds with metals, it is consequently more stable on the metal surface than comparable compounds containing a single sulfhydryl group that can create a dative bond.

m-dPEG®4-lipoamide was designed for stable passivation of gold or silver surfaces. For useful surface coating, it may prove helpful to create a mixed layer consisting of m-dPEG®4-lipoamide and another, longer dPEG® product with a lipoamido group on one end and reactive, affinity, or other functional groups on the opposite end. Thus, the short m-dPEG®4-lipoamide will form a uniform coating of methyl-terminated PEG above the metal surface, and the longer dPEG® product will rise above the dPEG® coating intermittently throughout the surface layer.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0), pp. 188-190, 458-497, 924-935.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Gastrointestinal Bioavailability of 2.0 nm Diameter Gold Nanoparticles. Candice A. Smith, Carrie A. Simpson, Ganghyeok Kim, Carly J. Carter, and Daniel L. Feldheim. ACS Nano. 2013, 7 (5) pp 3991–3996. April 21, 2013. DOI: 10.1021/nn305930e.

Description

m-dPEG®4-thiol, product number QBD-10792, is a short (14 atoms) monodisperse PEGylation reagent designed to modify gold and silver surfaces or biomolecules that contain free, surface-accessible thiols. One end of the spacer terminates with a methyl group, while the other end terminates with a sulfhydryl. The sulfhydryl group forms dative bonds with gold or silver, disulfides with free thiols, and thioether bonds with maleimide and bromoacetate groups.

This product is useful for the passivation of gold surfaces. The hydrophilic, non-immunogenic dPEG® spacer eliminates non-specific interactions with the gold surface.

If reacted with free thiols on biomolecules, m-dPEG®4-thiol forms disulfide bonds. Moreover, the resulting conjugates display improved water solubility and increased hydrodynamic volume. Furthermore, conjugation of this product with biomolecules potentially reduces or eliminates non-specific interactions and immunogenicity.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Gold nanoparticle-based fluorescence quenching via metal coordination for assaying protease activity. Se Yeon Park, So Min Lee, Gae Baik, Kim and Young-Pil Kim. Gold Bull. 2012, 45 pp 213–219. October 25, 2012. DOI: 10.1007/s13404-012-0070-9.

Polymerase Chain Reaction-Free Variable-Number Tandem Repeat Typing Using Gold Nanoparticle–DNA Monoconjugates. Jong Young Choi , Yong Tae Kim , and Tae Seok Seo. ACS Nano 2013, 7 (3) pp 2627–2633. February 12, 2013. DOI: 10.1021/nn400004d.

Near-Infrared-Activated Fluorescence Resonance Energy Transfer-Based Nanocomposite to Sense MMP2-Overexpressing Oral Cancer Cells. Yung-Chieh Chan, Ming-Hsien Chan, Chieh-Wei Chen, Ru-Shi Liu, Michael Hsiao, and Din Ping Tsai. ACS Omega. 2018,3 (2) pp. 1627-1634. February 8, 2018. DOI: 10.1021/acsomega.7b01494.

Magnetic Nanoparticle Tracking for One-Step Protein Seperation and Binding Kinetics Analysis. Yunlei Zhao, Guangzhong Ma, Shaopeng Wang. Journal of The Electrochemical Society. 2022. May 11, 2022. dx.doi.org/10.1149/1945-7111/ac6bc5.

NEW FRONTIERS FOR TRIPLE NEGATIVE BREAST CANCER DETECTION AND TREATMENT: FROM MECHANICAL BIOMARKERS TO SPECIFIC NANOPARTICLE ENTRY FOR ROBOTICALLY CONTROLLED LASER-INDUCED HYPERTHERMIA. Vanessa Uzonwanne. Worchester Polytechnic Institute. 2022. May 22, 2022.

Charge-Sensitive Optical Detection of Binding Kinetics between Phage-Displayed Peptide Ligands and Protein Targets. Runli Liang, Yingnan Zhang, Guangzhong Ma, Shaopeng Wang. MDPI. 2022. Biosensors 2022, 12(6), 394. June 8, 2022. https://doi.org/10.3390/bios12060394

Label-Free Single-Molecule Pulldown for the Detection of Released Cellular Protein Complexes. Guangzhong Ma, Pengfei Zhang, Xinyu Zhou, Zijian Wan, and Shaopeng Wang. ACS Cent. Sci. 2022, 8, 9, 1272–1281. 2022. https://doi.org/10.1021/acscentsci.2c00602

Description

m-dPEG®4-MAL, product number QBD-10745, is a thiol-reactive, single molecular weight, monodisperse PEG reagent that forms thioethers with sulfhydryls. The terminal maleimido group reacts rapidly and specifically at pH 6.5 – 7.5 with free thiols in a click chemistry type of reaction. The non-immunogenic dPEG® product increases the water solubility and hydrodynamic volume of conjugates made with it. Moreover, this product reduces or eliminates immunogenicity and non-specific interactions caused by hydrophobicity. This product is designed to modify small molecules, biomolecules, hydrogels, and surfaces (metal, glass, silica) containing free sulfhydryl groups.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0). See all of the extensive references to the reactions of maleimides with a variety of compounds and applications, Hermanson, p. 1174 (index for maleimides) and references therein.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Description

Azido-dPEG®4-OH (Azido-dPEG®4-alcohol), product number QBD-10541, is a click chemistry reagent used to modify surfaces and biomolecules or to crosslink with other surfaces or biomolecules in supramolecular construction. This product consists of an azide and a terminal hydroxy group separated by a short (14 atoms), single molecular weight, discrete-length polyethylene glycol (dPEG®) chain. The terminal azide reacts in copper(I)-catalyzed, ruthenium-catalyzed, and strain-promoted azide-alkyne cycloaddition reactions (CuAAC, RuAAC, and SPAAC, respectively). If left unmodified, the alcohol group increases the water solubility and hydrodynamic volume of molecules and surfaces to which it is conjugated. Modifying the alcohol with a reactive group such as chloride, tosylate, or mesylate allows Azido-dPEG®4-OH to function as a crosslinker through subsequent chemical manipulations.

As a click chemistry reagent, azido-dPEG®4-OH can participate in CuAAC, RuAAC, and SPAAC reactions. Because Vector Laboratories’ dPEG® products are amphiphilic, these reactions can occur almost equally well in water or organic solvents. Thus, azido-dPEG®4-OH can be used in conjugations with biomolecules where organic solvents may damage the conjugate target.

The primary alcohol group on the opposite end of the linker can be used as a neutrally charged functional group. In this function, the alcohol enhances the water solubility of the conjugate molecule. Alternatively, the alcohol group can be functionalized with reactive groups and used to modify the conjugate further.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Description

m-dPEG®4-azide, product number QBD-10532, also known as azido-m-dPEG®4, is a monodispersed PEG product used in click chemistry applications. A non-reactive, charge-neutral methyl group and an alkyne-reactive azido group, respectively, terminate the two ends of the short (14 atoms), single molecular weight, discrete PEG (dPEG®) spacer. Both metal-catalyzed (Cu(I), Ru) azide-alkyne cycloaddition (CuAAC, RuAAC) and strain-promoted azide-alkyne cycloaddition (SPAAC) work with this product. Possible click chemistry-based applications for this product include the construction of dendrimers and hydrogels and the modification of alkyne-functionalized surfaces or biomolecules containing alkyne groups.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Clickable Poly(ethylene glycol)-Microsphere-Based Cell Scaffolds. Peter K. Nguyen, Christopher G Snyder, Jason D. Shields, Amanda W. Smith, Donald L. Elbert. Macromolecular Journals. 2013, 214 (8) 948-956. March 4, 2013. DOI: 10.1002/macp.201300023.

Description

Azido-dPEG®4-acid, product number QBD-10502, is a click chemistry crosslinking reagent. The azide moiety on one end of the molecule is useful for copper(I)- or ruthenium-catalyzed click chemistry or copper-free click chemistry. Between the azide moiety and the propanoic acid moiety on the other end of the molecule is a single molecular weight, discrete polyethylene glycol (dPEG®) spacer. The propanoic acid moiety can be coupled to a primary or secondary amine by an acylation reaction. The azide also functions as a masked amine. In this application, the carboxylic acid end reacts first with an amine to form a peptide bond, followed by reduction of the azide to an amine for further reaction.

Activation of the propanoic acid moiety with an acylating agent enables conjugation of azido-dPEG®4-acid to a primary or secondary amine. Popular acylating agents include such as N-hydroxysuccinimide (NHS); 2,3,5,6-tetrafluorophenol (TFP); or 2,3,4,5,6-pentafluorophenol (PFP). Alternatively, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) or another suitable carbodiimide can be used to couple the acid moiety directly to an amine without prior activation.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Click Chemistry on Solution-Dispersed Graphene and Monolayer CVD Graphene. Zhong Jin, Thomas P. McNicholas, Chih-Jen Shih, Qing Hua Wang, Geraldine L. C. Paulus, Andrew J. Hilmer, Steven Shimizu and Michael S. Strano. Chemistry of Materials. 2011, 23(1) pp 3362-3370. June 30, 2011. DOI: 10.1021/cm201131v.

“Click” Immobilization of a VEGF-Mimetic Peptide on Decellularized Endothelial Extracellular Matrix to Enhance Angiogenesis. Lin Wang, Meirong Zhao, Siheng Li, Uriel J. Erasquin, Hao Wang, Li Ren, Changyi Chen, Yingjun Wang, and Chengzhi Cai. ACS Applied Materials and Interfaces. 2014, 6(11) pp 8401-8406. April 21, 2014. DOI: 10.1021/am501309d.

The carbohydrate-linked phosphorylcholine of the parasitic nematode product ES-62 modulates complement activation. Umul Kulthum Ahmed, N. Claire Maller, Asif J. Iqbal, Lamyaa Al-Riyami, William Harnett, and John G. Raynes. The Journal of Biological Chemistry. 2016, April 4, 2016. DOI: 10.1074/jbc.M115.702746.

Biomolecular Strategies for Cell Surface Engineering. John Tanner Wilson. Doctoral Dissertation, Georgia Institute of Technology: Atlanta, Georgia USA, 2009.

Multistage signal-interactive nanoparticles improve tumor targeting through efficient nanoparticle-cell communications. Feng Zhang, Yiran Zhang, Li Kong, Huanhuan Luo, Yuezhou Zhang, Ermei Mäkilä, Jarno Salonen, Jouni T.Hirvonen, Yueqi Zhu, Yingsheng Cheng, Lianfu Deng, Hongbo Zhang, Alexander Kros, Wenguo Cui, Hélder A.Santos.Cell Reports. 2021, Volume 35, Issue 8. 05/25/2021. DOI: 10.1016/j.celrep.2021.109131

Description

MAL-dPEG®4-acid, product number QBD-10338, is a short (16 atoms) crosslinker that joins sulfhydryl groups to free amines through a single molecular weight polyethylene glycol (PEG) chain of discrete length. The maleimidopropyl moiety reacts with sulfhydryl groups via a Michael addition reaction. The propionic acid terminus of the molecule reacts directly with free amines using EDC or another carbodiimide to form amide bonds. Alternatively, activation of the propionic acid group with N-hydroxysuccinimide (NHS), 2,3,5,6-tetrafluorophenol (TFP), or some other acylating agent permits amide bond formation under mild, controlled conditions.

Chemical couplings between free amines and free thiols are among the most popular, most useful crosslinking reactions in bioconjugate chemistry. These syntheses require heterobifunctional reagents that bridge the two groups. While traditional crosslinkers are hydrophobic molecules, Vector Laboratories’ crosslinking products are water-soluble, amphiphilic, single molecular weight PEG compounds with discrete chain lengths, hence the dPEG® tradename under which we sell them. Almost inevitably, the conjugation of conventional hydrophobic crosslinking reagents to biomolecules triggers problems such as aggregation and precipitation of the conjugates. Conversely, these problems do not occur with our water-soluble, non-immunogenic dPEG® crosslinkers.

The reaction of the maleimide end of MAL-dPEG®4-acid with a sulfhydryl proceeds optimally at pH 6.5 – 7.5. Use the lowest reasonable pH within this range. Above pH 7.5, free amines compete with free thiols at the maleimide reaction site, which can cause confusing results. Moreover, at higher pH values, the maleimide ring may open to form unreactive maleamic acid.

After the maleimide end of the molecule reacts with a sulfhydryl, the terminal propionic acid group may be left unreacted for charge modification or the conjugate or activated with an acylating agent such as NHS or TFP. The active ester then reacts with free amines to complete the crosslink.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 2nd Edition, Elsevier Inc., Burlington, MA 01803, April, 2008 (ISBN-13: 978-0-12-370501-3; ISBN-10: 0-12-370501-0); See pp. 276-335 for general description and use of heterobifunctional crosslinkers, and the specific sample protocol for SMCC or sulfo-SMCC on pp. 283-286.

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Description

Methoxytrityl-S-dPEG®4-acid, product number QBD-10301, permits the introduction of a protected thiol-dPEG® spacer/linker onto a molecule by reaction with a free amine. The methoxytrityl (Mmt) protected thiol deprotects under mild conditions using dilute trifluoroacetic acid (TFA) with a scavenger. This compound is useful in peptide synthesis and modification, where a free thiol must be introduced into the parent molecule.

Product number QBD-10301 permits our customers to insert a short (16 atom, 18.3Å) dPEG® into a peptide chain using familiar solid phase or solution phase chemistry. Upon activation, Methoxytrityl-S-dPEG®4-acid reacts with any free amine. This allows for a broad range of situations where this product can be employed to convert an amine to a thiol. The dPEG® can be inserted at the N-terminus of a peptide chain or on any amino acid side chain with an exposed free amine. In addition, the short dPEG® spacer can be used simply to provide additional distance in a synthetic construct where steric hindrance is a problem. The amphiphilic nature of dPEG® means that the construct will gain some degree of water solubility while remaining soluble in organic solvent. The Mmt protecting group removes relatively easily with a dilute solution of TFA that also contains a scavenger such as triethylsilane (TES) or triisopropylsilane (TIPS). Once the thiol group is deprotected, it can be reacted with another thiol to form a disulfide bond or with any thiol-reactive group such as maleimide, bromoacetamide, alkene (thiol-ene reaction) or alkyne (thiol-yne reaction).

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.

Gold Nanoparticles Functionalized with Peptides for Specific Affinity Aggregation Assays of Estrogen Receptors and Their Agonists. Yoshiyuki Takatsuji, Shinya Ikeno and Tetsuya Haruyama. Sensors. 2012, 12 (4), pp 4952-4961. April 18, 2012. DOI: 10.3390/s120404952.

Description

CBZ-N-amido-dPEG®4-acid, product number QBD-10268, is a benzyl carbamate (Cbz) N-protected amino-dPEG®-acid that provides a short, single molecular weight discrete PEG (dPEG®) spacer. Designed for use in peptide synthesis, it can also be used in many other reactions. In peptide synthesis, the removal of the Cbz protecting group is orthogonal to many other protecting groups.

The Cbz protecting group (also called the Z protecting group) is one of the most popular protecting groups for amines. It is stable in mildly basic and acidic conditions. A variety of methods cleave the Cbz group. The most popular cleavage technique is hydrogenolysis, using palladium black or palladium on carbon.

Specifications

Documents

References

Greg T. Hermanson, Bioconjugate Techniques, 3rd Edition, Elsevier, Waltham, MA 02451, 2013, ISBN 978-0-12-382239-0; See Chapter 18, Discrete PEG Reagents, pp. 787-821, for a full overview of the dPEG® products.