Lysine residues alkaline phosphatase

Rothman and Byrne 46) have used tryptic digestion to determine whether the subunits of alkaline phosphatase are identical. Since trypsin specifically cleaves at lysyl and arginyl residues, there will be as many peptides formed as there are arginine and lysine residues if the mono-... 

Reaction of a 2000-fold molar excess of 5-diazonium-lH-tetrazole (DHT) with alkaline phosphatase, reduces hydrolase activity to 36% and phosphotransferase activity to 29% of the control. Since no color was produced by the reaction it was assumed that the reaction occurred with lysine residues. When the concentration of DHT is a 20,000-fold molar excess, color develops and the hydrolase activity falls to 11% while the phosphotransferase activity falls to 47%. In this later DHT reaction, the spectral maxima produced are characteristic of azotyrosine and azohistidine (91). 

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