PHOSPHORYLATION AND INACTIVATION OF AMINOGLYCOSIDIC ANTIBIOTICS BY E. COLI CARRYING R FACTOR
1968 年 21 巻 1 号 p. 13-21
詳細
1968 年 21 巻 1 号 p. 13-21
An enzyme solution was prepared by centrifugation at 100, 000xg of disrupt cells of E. coli K12 ML1629 carrying R factor. It inactivated kana mycin, streptomycin and paromamine. This enzyme solution required ATP and Mg++ for inactivation of these antibiotics, but not coenzyme A and acetate.
One of the inactivation products of kanamycin recovered activity by treatment with alkaline phosphatase. The activity of inactivated paromamine was restored by the alkaline phosphatase. Thus, the inactivation was suggested to be due to phosphorylation. The enzyme solution prepared from the sensitive strain, E. coli K12 (CS-2) and its subcultures which had been made resistant by transfers in kanamycin medium showed no inactivation of kanamycin, and thus the formation of enzymes for inactivation was characteristic of the strain carrying R factor. Alkaline phosphatase formation in E. coli K12 ML1629 is repressed by phosphate at a lower concentration than that in E. coli K12 (CS-2). The enzyme solution prepared from E. coli K12 (CS-2) which grew under conditions repressing formation of alkaline phosphatase showed no inactivation of kanamycin. The sensitivity of E. coli K12 (CS-2) and E. coli K12 ML1629 to kanamycin was not influenced by the presence or absence of alkaline phosphatase repression. It was shown that phosphorylative inactivation is one of the mechanisms of resistance of E. coli carrying R factor.
