Select the thiol state of the system.
state: The thiol state.
The thiol state can be any text, thought the BMRB suggests the following:
Alternatively the pure states `reduced' or `oxidised' could be specified.
For BMRB deposition, to say that the protein studied is in the oxidised state, tyype one of:
[numbers=none] relax> bmrb.thiol_state('oxidised')
[numbers=none] relax> bmrb.thiol_state(state='oxidised')