Assignment of nucleotide protons by 2D NOESY spectra

4 posts / 0 new
Last post
anupguru
anupguru's picture
Assignment of nucleotide protons by 2D NOESY spectra

 I have a question why is the resonance  assignment of DNA nucleotide starts with assignment of thymine and cytosine aromatic protons in case of non-exchangeable proton assignment ?

Sami Tuomivaara
Sami Tuomivaara's picture
anupguru,

anupguru,

Thymine and cytosine have coupled protons that give a cross-peaks in the COSY experiment (for cytosine C6H and C5H and for thymine, methyl group and C6H). This kind of coupled protons do not exist in guanine and adenine. These cross-peaks are convenient starting point in the assigment prcedure.

Cheers,

anupguru
anupguru's picture
 Thanking You for your reply.

 Thanking You for your reply.

Regards,

Anup

anupguru
anupguru's picture
respected sir/madam,

respected sir/madam,

How is the imino and amino proton assigned in exchangeable proton assignment?

And after all, if all the protons are assigned , how is actually the proton distances calculated to predict a structure?

Regards

anup chowdhury