Abstract: TOCSY which provides relay informatoins overall protons in spin coupling network is a new development of RELAY. It is especially suitable for large molecules which have several independent spin systems.
In this paper, MLEV-17 sequence has been used for TOCSY both in homo-and heteronuciear coherence experiments and two polypeptides have been analysed.

Key words: TOCSY, RELAY, Polypeptide, Analysis