Diagnosing Elevated Levels of Nitrated Tyrosine in Disease

Nitrosation and nitration of tyrosine residues are diagnostic features for conditions such as asthma, atherosclerosis, Alzheimer’s disease, inflammation, ischemia, Parkinson’s disease and Cancer. The researchers have developed a fast and efficient method to accurately quantify nitrated tyrosine residues directly from biological samples. The method is also suitable for assessing the nitrative stress of cells.

The method includes azo coupling of nitro or aminotyrosine to a target compound (e.g. napthylamine). The target compound produces a pH dependent colorimetric signal, making it very easy to identify the reaction product. The signal can further be quantified, by mass spectrometry, to determine the identity and precise concentration of nitrated tyrosine in the sample. The method is applicable for nitrotyrosine containing peptides, their reduced forms (aminotyrosine) as well as their diazotyrosine derivatives. Other amino acids (histidine, tryptophan) or nulceotides (guanosine) which are targets for nitration can also be identified similarly. 

Applications

• Detect levels of nitrated tyrosine in proteins and peptides
  
• Diagnose diseases involving elevated nitrated tyrosine

Advantages

• Applicable to all targets of nitration in proteins, peptides and nucleotides
  
• Easy colorimetric identification of reaction product
  
• Compatible with mass spectrometry for enhanced accuracy