these procedures were carried out using the methodology that has been developed to allow for the detection of phosphoproteins containing 1-p-histidinyl and 3-p-histidinyl residues , and also to distinguish between these and phosphoproteins containing acid-stable phosphoamino acids such as phosphoserine , phosphothreonine , and phosphotyrosine .
C0524823
phosphoamino acids
C0031721
phosphoserine