how to make standard curve of tyrosine. - (Jul/17/2009 )
Think following might help.
One unit of the alkaline protease activity (U) was defined as the amount of enzyme liberating 1 μg of tyrosine per min per ml under the assay conditions
Production of alkaline protease from an alkaliphilic actinomycete
Volume 97, Issue 14, September 2006, Pages 1650-1654