Thermo Scientific Pierce EMCH is a mid-length, maleimide-and-hydrazide crosslinker for conjugating sulfhydryls (cysteines) to carbonyls (aldehyde or ketones, such as those formed by oxidation of glycoprotein carbohydrates).
3,3´-N-[ε-Maleimidocaproic acid] hydrazide, trifluoroacetic acid salt (EMCH) is a water-soluble, heterobifunctional, membrane permeable crosslinker. It contains a sulfhydryl reactive maleimide group and carbonyl reactive hydrazide group at each end of a 6-carbon spacer arm. Maleimides react with sulfhydryls at pH 6.5-7.5 to form stable thiol ether bonds, along with release of the maleimide leaving group. Proteins with cysteine residues not involved in disulfide bond formation are targets for maleimide reactive groups. Carbonyl groups, whilst not found naturally on proteins can be formed by ring sugar reduction to form aldehydes which react with hydrazides at pH5.5-7.5.
- Reactive groups: maleimide and hydrazide
- Reactive towards: sulfhydryl groups and carbonyl (aldehyde) groups
- Mid-length (11.8A), sulfhydryl-to-aldehyde crosslinker with simple spacer arm (noncleavable)
- Maleimide group reacts with sulfhydryl groups to form stable thioether linkages
- Hydrazide group conjugates to oxidized sugars of glycoproteins and carbohydrates
- Use sodium meta-periodate to oxidize glycosylation (e.g., sialic acid) to reactive aldehyde groups
- Use with EDC to conjugate primary amine of hydrazide group to carboxyl groups
- Chemical crosslinking of glycoproteins to sulfhydryl-containing molecules
- Use with EDC for reactivity toward carboxyl groups
|Chemical structure of EMCH crosslinking reagent.
Properties of EMCH.
|Spacer arm length
||11.8 Å (6 atoms)
||4°C, protect from moisture, use only fresh solutions
||Maleimide, reacts with sulfhydryls at pH 6.5-7.5
||Hydrazide, reacts with carbonyls at pH 5.5-7.5
Specifications of EMCH:
We manufacture EMCH to the highest specifications to produce the most specific bioconjugates, ensure the integrity of your data and to provide you with the highest degree of consistency. Each lot of EMCH is tested to meet the following minimum specifications.
- NMR purity: >90%
- Melting point: 99-110°C
- Identity: IR scan shows only peaks characteristic of the structure and functional groups of EMCH
- Trail, P.A., et al. (1993). Science 261, 212-215.
Crosslinker Application Guide -- search for recent literature references for this product
Overview of crosslinking
Chemistry of crosslinking
Protein glycosylation technical guide
Crosslinkers at a glance (selection guide)