Lividomycins activity

Resistance to lividomycin. Lividomycin is a new aminoglycoside pentasaccharide antibiotic containing 2-deoxystreptamine (Figure 7.13) [200]. The activity of lividomycin against strains of Ps. aeruginosa is similar to that shown by streptomycin (Table 7.17). Lividomycin is not phosphory-lated by the neomycin kanamycin phosphotransferase because it lacks the 3 -hydroxyl group [212]. However, recently the presence was reported... 

Table 7.16. ANTIBACTERIAL ACTIVITY OF LIVIDOMYCIN AGAINST SENSITIVE AND RESISTANT STRAINS OF PS. AERUGINOSA [200]...

Deoxylividomycin and 5"-amino-5"-deoxylividomycin have recently been synthesised [214] and, as expected, are not substrates for lividomycin phosphotransferase since they lack the hydroxyl moiety on the 5"-position of the D-ribose ring. Although these synthetic antibiotics are less potent than lividomycin, they show greater activity against strains producing the phosphorylating enzyme. 

Partial purification of the lividomycin-inactivating enzyme was attempted by Mitsuhashi and coworkers, who briefly described their discovery that the enzyme obtained by fractionation with ammonium sulfate and column chromatography on Sephadex G-lOO inactivates lividomycins A and B, but not kanamycin A, indicating involvement of two different enzymes in the phosphorylation of lividomycin and kanamycin. However, it was definitely proved by H. Umezawa and coworkers that kanamycin-neomycin phosphate transferase I phosphorylates the 5"-hydroxyl group of lividomycins. The observation by Mitsuhashi and coworkers was probably occasioned by instability of the enzyme and the higher activity of the enzyme in phosphorylating lividomycins than in phosphorylating kanamycin A. 

The lividomycin A-Sepharose 4B was packed in a column (1.0 X 11.7 cm 9 ml) and washed with 20 mM Tris hydrochloride buffer containing 10 mM magnesium acetate, 60 mM potassium chloride, and 10 mM 1,4-dithiothreitol, and 5 ml of the supernatant liquor from the disrupted cells was passed through the column at the rate of 40 ml/hour. The enzyme adsorbed was successively eluted with a gradient of sodium chloride (0 to 0.8 M) in 20 mM Tris-hydrochloric add buffer, pH 7.2. The enzyme that phosphorylates and inactivates both lividomycin A and kanamycin appeared in the eluate made with 0.4 to 0.6 M sodium chloride. By this procedure, the enzyme was purified 25- to 40-fold in phosphorylating activity for both kanamycin A and lividomycin A. The purified fraction obtained showed two bands in disc-gel eledrophoresis, and one of the bands had the activity as regards phosphorylating kanamycin A and lividomycin A. 

The appearance of kanamycin and lividomycin A phosphorylating activities in the same peak in the chromatography, and the mutual, competitive inhibition of the phosphorylation by these antibiotics, constitute enough proof of the involvement of a single enzyme in the phosphorylation of kanamycin and lividomycin A. 

The analogue (23) of lividomycin B (24) and the 2"-substituted regioisomer have been synthesized to test the effect of the N-1 butanoyl substituent on the activity of their N-1 unsubstituted... 

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