Purification of Aminoglycoside

Sir: In 1967, UMEZAWA et al.1) found a kanamycin-neomycin phosphotransferase in Escherichia coli carrying R factor and proved that the resistance is directly related to the formation of this enzyme.2) In 1972, YAGISAWA et al.3) found another phosphotransferase in E. coli carrying a different R factor. These enzymes were different in their substrate specificities. The former which is now called aminoglycoside phosphotransferase I (APH(3')-I) transfers phosphate from ATP to the 3'hydroxyl group (the 3-hydroxyl group of the 6amino-6-deoxy-D-glucose moiety) of kanamycin and also to the 5"-hydroxyl group (the 5hydroxyl group of the D-ribose moiety) in lividomycin A but not to the 3'-hydroxyl