What is protein nitration?
For proteins it represents a post-translational modification that occurs primarily on tyrosine residues. The effect of which seems to vary greatly.
A recent study published in PNAS entitled: "Nitration of Hsp90 induces cell death" describes how nitration as a result of oxidative stress can turn a normally helpful protein into a toxic protein. This 90 kDa heat-shock protein is a part of the highly conserved family of proteins that are well characterized for their function as chaperones. So for Hsp 90 to be able to convert into a protein that induces cell death may, at first, seem illogical. However, since Hsp 90 plays a role in up to 200 cell functions, when it is shut down by tyrosine nitration, all of those cell functions are adversely affected.
The presence of tyrosine nitrated Hsp 90 is seen in a number of different pathologies and it is hoped that finding a drug that protects against tyrosine nitration may provide protection for a variety of degenerative diseases.
One of the main antioxidant systems employed to keep oxidative stress at bay is the thioredoxin reduction pathway. BMG LABTECH application note #167 describes how thioredoxin activity can be studied in neurons and glial cells using the FLUOstar OPTIMA.