원문정보
초록
영어
The identification of the substrate specificity of a protein kinase is critical in understanding its role and function in a cellular signal transduction network. [1,2] Here, a new high-throughput system was developed to identify the substrate specificity of PTKs, p60c-src and ZAP-70, using a fully randomized "one-bead one-compound"(OBOC) combinatorial peptide library constructed by ladder synthesis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). As expected from previous studies, the substrate specificity of p60c-src showed that acidic amino acids (Glu and Asp) at the +1 and +2 positions and Ile at the -1 position are necessary for efficient tyrosine residue phosphorylation. To generalize our method, the substrate sequence identification of ZAP-70 tyrosine kinase was carried out. Interestingly, glutamic acid (Glu) at the +2 and +1 position appeared most frequently (49% and 21%) according to the sequence analysis. Aspartic acid (Asp) at the +2 position was the second most frequently appearing residue (29%). Moreover, Glu and Asp were shown to be the most likely amino acids present at the -1 position, but there was no selectivity at the -2 position. In addition, the annotation of potential target proteins for the p60c-src and ZAP-70 kinase signal
transduction pathway was undertaken using the SwissProt database.