DABITC isothiocyanate

A couplingreagent 1.4 mg DABITC (4-(dimethylamino)azoben-zene-4 -isothiocyanate, Mr 282.4, recrystallized from acetone) is dissolved in 1.0 ml acetone. The solution is divided into 40 pi aliquots, and acetone is evaporated by nitrogen. The aliquots are stable in a desiccator at room temperature for months. 

B 2. The new reagent 4-W,W-dimethylaminoazobenzene-4 -isothiocyanate (DABITC) is often used for the Edman method of protein sequence analysis. Write a reaction showing this use of the reagent. 

Phenyl isothiocyanate is also used for peptide sequencing in combination with colored Edman s reagent 4-W-,/V -dimethy]aminoazobenzene-4 -isothiocyanate (DABITC). Prieto (48) used this DABITC-PITC procedure to determine the partial terminal N-NH2 sequence of the low-molecular-weight peptide fraction from bread dough and bread. 

Amino acids derivatized with isothiocyanates (PITC, NITC, DNITC, DABITC), with AQC. or with sulphonyl chlorides (DNS-Cl. DABS-CI)... 

Dimethylamino azobenzene isothiocyanate microsequencing results in red-orange derivatives, which exhibit their absorbance maximum at 420 nm with s = 47.000, in other words offering threefold higher sensitivity compared to PTH derivatives. DABITC deriva-... 

CAPS, 3-[cyclohexylamino]-l-propanesulfonic acid DABITC, dimethylaminoazobenzene isothiocyanate DABTH, dimethylaminoazobenzene thiohydantoin OPA, o-phthalaldehyde PTC, phenylthiocarbamyl PTH, phenylthiohydantoin PVDF, polyvinylidine difluoride TFA, trifluoroacetic acid... 

The identification of N-terminal amino acids in peptides and proteins is of considerable practical importance because it constitutes an essential step in the process of sequential analysis of peptide structures. Many N-amino acid derivatives have been proposed for this purpose and the ones most commonly studied by TLC are 2,4-dinitrophenyl (DNP)-and 5-dimethylaminonaphthalene-l-sulfonyl (dansyl, Dns)-amino acids, and 3-phenyl-2-thiohydantoins (PTH-amino acids). Recently, 4-(dimethylamino)azobenzaie-4/-isothio-cyanate (DABITC) and phenyl-isothiocyanate (PITC) have also been investigated as derivatizing agents of amino acids. 

The classical method is the Edman degradation reaction. It involves stepwise degradation of peptides with phenylisothiocyanate (cf. 1.2.4.2.3) or suitable derivatives, e. g. dimethylaminoa-zobenzene isothiocyanate (DABITC). The resultant phenylthiohydantoin is either identified directly or the amino acid is recovered. The stepwise reactions are performed in solution or on peptide bound to a carrier, i.e. to a sohd phase. Both approaches have been automated ( sequencer ). Carriers used include resins containing amino groups (e. g. amino polystyrene) or glass beads treated with amino alkylsiloxane ... 

Dimethylamino)azobenzene-4-isothiocyanate. 4-Dimethylamino-4 -isothiocyanatoazobenzene. DABITC [7612-98-8]... 

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