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Site‐directed mutagenesis of AMP‐binding residues in adenylate kinase Alteration of substrate specificity
Author(s) -
Okajima Toshihide,
Tanizawa Katsuyuki,
Fukui Toshio
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)81687-u
Subject(s) - adenylate kinase , enzyme , site directed mutagenesis , chemistry , biochemistry , mutant , substrate (aquarium) , mutagenesis , phosphorylation , kinase , enzyme assay , microbiology and biotechnology , biology , gene , ecology
Adenylate kinase is highly specific for AMP as phosphoryl acceptor. We have found that the replacement of Thr 39 by Ala in the chicken muscle enzyme, alone or together with the replacement of Leu 66 by Ile, caused remarkable increases in CMP and UMP activities with a concomitant decrease in AMP activity; therefore, the resulting mutant enzymes show CMP and UMP activities/AMP activity ratios much higher than the wild‐type enzyme. The mutant enzyme in which Ala is substituted for Thr 39 has a V max value for CMP comparable to that of CMP‐UMP kinase.