Question

Which is main reactant of edman's reagent used in protein sequencing?

Answer 1

Edman degradations, with many modifications to sequenators and conditions within, and the sequencing following the degradations, were (and possibly are) valuable in finding protein amino acid composition today, even though various other techniques have superseded them in popularity, efficiency, and accuracy, some of which are just modifications of the original degradation. Note that I said that "sequencing" and "Edman degradations" are completely different things- that's because they are both physically and conceptually separate. One governing principle here is that DNA sequencing is "light-years ahead" of protein sequencing, and these types of sequencing techniques are usually designed to identify one protein that's already been highly purified, not a soup of mixed proteins, comparable to DNA sequencing.

Let's address the organic chemistry of Edman degradations (the degradations themselves) first. Then we can talk about sequencing methods, which are much higher in number and, to some degree, complexity. The "why" of most of the sequencing is in the degradation procedure.

Answer 2

Edman degradation play an important role in locating protein amino acid composition.

Phenylisothiocyanate is regarded as the Edman reagent.

It is the primary component of the degradation procedure
The reagent plays a very important role in the breaking of the peptide bonds. C-S is the bond used to attack the N termini.