LI-COR offers click chemistry reagents / dyes

Li-Cor, the company of "environmental and biotechnology research systems", started to offer click chemistry reagents. 

They combined click chemistry with its unique long-wavelength Infrared dyes. Dyes include: IRDye 800CW, TRDye 680RD, IRDye 650. Click chemistry gourps include: dibenzocyclooctyne (DBCO), azide and alkyne. The coupling of above (3x3) generated 9 reagents - for click chemistry in the field of in vitro or in vivo labeling and tracking of biomolecules. Options are available with copper-catalyzed and copper-free versions of click chemistry. 

A webinar is provided for viewers.

Protein methylation study by click chemistry

Bioorthogonal Profiling of Protein Methylation Using Azido Derivative of S-Adenosyl-L-methionine, Minkui Luo, et al, J. Am. Chem. Soc. 2012, 134, 5909-5915
dx.doi.org/10.1021/ja2118333

A few key points:
1. Protein methytransferase transfers methyl group from  S-Adenosyl-L-methionine (SAM) to specific proteins.
2. Selective mutation of a transferase allows its acceptance of modified azido-SAM. 
3. Instead of methyl group, the azido-R group was transferred to specific proteins in cells with above SAM transferase.
4. Copper-free Click chemistry and MS reveal the identity of the specific methylated protein.
5. Therfore, methyltransferase - target protein link is established.  

Labeling of live cells via Copper-catalyzed click chemistry

Copper-free click chemistry developed by Bertozzi Group allowed in vivo labeling and imaging of glycans without copper toxicity. This was reported widely by many media and scientific magazines. A summary on this topic will be given elsewhere.
 
Now two reports appeared using Copper-catalyzed click chemistry for the same purpose. The key is the identification of good ligands for Copper (1+) ion which allow for rapid labeling and minimal toxicity.
 
Vu Hong, M. G. Finn et al, "Labeling Live Cells by Copper-Catalyzed Alkyne-Azide Click Chemistry", Bioconj. Chem. received 6/17/2010.
Rapidly labels mammalian cells in culture with no loss in cell viability. Metabolic uptake and display of the azide derivative of N-acetylmannosamine (Bertozzi) followed by CuAAC reaction with dye-alkyne  

David Soriano del Amo, Peng Wu et al, "Biocompatible Copper(I) Catalysts for in Vivo Imaging of Glycans", JACS received 7/23/2010.
Rapid labeling and imaging of fucosylated glycans during zebrafish early embryogenesis without apparent toxicity. Alkyne-bearing  GDP-fucose microinjected and CuAAC reaction with dye-azide. 
                                            

BARAC - yet another strain-promoted copper-free click chemistry

Believe it or not, this one is called BARAC. 

Click chemistry is certainly not "done". This time, instead of electronic properties, Bertozzi group looked at the strain energy by introducing some level of double bond nature into the octyne ring structure. The choice was amide bond which displays well-known partial double bond nature (C=N). "Brushing against the line between stability and reactivity without crossing it", this is another beautiful example of "rational design" in physical organic chemistry. "Gratifying", The click reaction rate was superior, 12-fold faster than DIFO the difluoro-version. The group then evaluated BARAC derivatives in their "traditional" cell glycobiology imaging where cell surface carries glycan azide. It demonstrates superior performance than DIFO and DIBO. Modular and scalable synthesis of BARAC offers more opportunities and wider applications of this new copper-free click chemistry. 

Champagne finished, time to work on the next click chemistry.

Journal of the American Chemical Society, 2010, DOI 10.1021/ja100014q