PTAD-Azide ALD00344-50MG

Empirical Formula (Hill Notation):	C10H10N6O3
CAS Number:	1313211-52-7
Molecular Weight:	262.22
MDL number:	MFCD25976544
PubChem Substance ID:	329772652
NACRES:	NA.22

PTAD-Azide (4-(4-(2-Azidoethoxy)phenyl)-1,2,4-triazolidine-3,5-dione) is a 1,2,4-triazolidine-3,5-dione derivative. It can be prepared from ethyl hydrazinecarboxylate.
PTAD-Azide is a selective crosslinking reagent that has one end for reacting with tyrosine and the other end for presenting an azide. After bioconjugation to tyrosine, the azide can be reacted with an alkyne through the Cu(I)-catalyzed click chemistry reaction or with a cyclooctyne in a copper-free reaction. This reagent has been shown to selectively introduce poly(ethylene glycol) or PEG chains onto proteins with surface exposed tyrosine residues. PTAD-Azide has also been used in the formation of antibody-drug conjugates. This reagent is compatible with different buffer systems such as PBS, Tris and mixed PBS/Tris buffer (preferred). The linkage with tyrosine has been shown to be stable to pH and temperature extremes as well as blood plasma.
Note: PTAD-Azide must be first activated by stirring in a 1:0.98 molar ratio with 1,3-dibromo-5,5-dimethylhydantoin (product # 157902). Activation is evident upon solution color change from colorless to deep red and the activated reagent should be used immediately.

General Procedure for Protein Modification with PTAD.
Part 1: PTAD activation

• Mix together 1:0.98 molar equivalents of unactivated PTAD to 1,3-dibromo-5,5-dimethylhydantoin (product # 157902) in organic solvent (preferred solvents are DMF or acetonitrile, avoid using DMSO)
• Color change is observed from colorless/pale yellow to deep red (approximately 5 min of mixing).
• After the solution turns red, store the now activated reagent on ice and use for protein modification within 30 min.

Part 2: Protein modification

• Add protein solution in mixed phosphate/Tris buffer or Tris buffer (pH should be 6 - 9) to the eppendorf tube (or other vial) containing the activated PTAD reagent prepared above and mix gently at room temperature for up to 30 min. Preferably use 10-fold molar excess of reagent relative to protein. Use protein at a minimum concentration of 1 mg/ml (higher concentrations are preferred for enhanced labeling).
• Remove excess unreacted PTAD by gel filtration.

PTAD-Azide may be used in the preparation of 4-(4-(2-azidoethoxy)phenyl)-3H-1,2,4-triazole-3,5(4H)-dione and aplaviroc-urazole. This urazole was recently demonstrated in the traceless, chemoselective labeling of peptides and proteins through electrochemical tyrosine-click (e-Y-CLICK) chemistry.
Packaging
50 mg in glass bottle
Electrochemically Promoted Tyrosine-Click-Chemistry for Protein Labeling,

Quality Level	100,
assay	95%
form	powder or crystals
reaction suitability	reagent type: cross-linking reagent
storage temp.	2-8°C
SMILES string	O=C(NNC1=O)N1C2=CC=C(OCCN=[N+]=[N-])C=C2
InChI	1S/C10H10N6O3/c11-15-12-5-6-19-8-3-1-7(2-4-8)16-9(17)13-14-10(16)18/h1-4H,5-6H2,(H,13,17)(H,14,18)
InChI key	MHGMHPVYCVQIET-UHFFFAOYSA-N

RIDADR	NONH for all modes of transport
WGK Germany	WGK 1
Flash Point F	Not applicable
Flash Point C	Not applicable