Blasticidins

Aminohexose Nucleosides. The 4-aminohexose nucleosides (128—140) are Hsted in Table 7 (1—4,240—242). A biosynthetic relationship between the 4-aminohexose peptidyl nucleoside antibiotics and the pentopyranines has been proposed (1). The 4-aminohexose pyrimidine nucleoside antibiotics block peptidyl transferase activity and inhibit transfer of amino acids from aminoacyl-tRNA to polypeptides. Hikizimycin, gougerotin, amicetin, and blasticidin S bind to the peptidyl transferase center at overlapping sites (243). 

Kitagawa, T., Kawasaki, T., and Munechika, H. (1982) Enzyme immunoassay of blasticidin S with high sensitivity a new and convenient method for preparation of immunogenic (hapten-protein) conjugates. J. Biochem. (Tokyo) 92, 585-590. 

D-Glucofuranosylamine)uronic acids attained biological significance after nucleoside antibiotics containing hexuronic acid residues were isolated from natural sources examples are gougerotin and blasticidin S. 

Actinomycin D, Antibiotic 205-2B, Blasticidin, Cycloheximide(actidione), Daunomycin DPB, Mithramycin, Mitomycin C, Pentaene G8, and Tubercidin. 

Blasticidins are produced by Streptomyces grieseochro -mogens and inhibit several species of bacteria and fungi (31). Pseudomonas is particularly vulnerable to blasticidin S. Piricularia oryzae causing the blast disease of rice is widely controlled with blasticidin S in Japan. It is applied to the rice plants after infection by the fungus has already ocurred(32), since the antibiotic affects the myce -lial phase more than the spore phase. It would be desirable to search for spore killing antibiotics to control soil-inhabiting microbes and to destroy the inoculum before it infects the crop. 

Actidione5Actinomycin D, Blasticidin, Chloramphenicol, Citrinin, Daunomycin, Dextro-mycin, Ferrimycidin, Formycin, Imanin, Kanamycin, Laurisin, Miharamycin, Mitomycin C, Naramycin, Ohyamycin, Pentaene G8, Polyoxin A, Puromycin, Streptomycin. 

Fill the cylinder with complete medium and slowly pipette up and down several times to detach the cells. Transfer each cell clone into a well of a 24-well plate previously filled with complete growth medium supplemented with blasticidin (see Note 8). 

Clones have to be maintained in selective medium containing blasticidin (see Note 14). 

Select the clones with the appropriate concentration of the two antibiotics (blasticidin to maintain Tet-repressor construct and puromycin for the shRNA-expressing construct) changing medium every 3 or 4 days. 

Wait at least 24 h after transfection to allow for sufficient expression of the resistance gene before adding antibiotics. Include two plates as controls one plate of transfected cells without antibiotic selection as positive control for cell viability and another plate of untransfected cells, seeded at the same density and treated with blasticidin to monitor cell resistance and antibiotic activity. All cells should die in this control under antibiotic selective pressure. 

There are a variety of natural antibiotics which contain a pyrimidine or reduced pyrimidine ring <2005CBI1>, and several of these are used therapeutically for a number of different applications. Blasticidin S and the polytoxins were mentioned in the section on antifungals, but other examples include amicetin, capreomycin, gougerotin, and viomycin, as well as the bleomycins and phleomycins. 

The bromide monohydrate was also used71 in establishing the crystal structure of blasticidin S. The dimensions of the unit cell (a =... 

There are two commercial fungicides, the antibiotics blasticidin S and kasugamycin, that act via the inhibition of protein biosynthesis (Figure 4.19). Blasticidin S is a fermentation product obtained from cultures of Streptomyces griseochromogenes, and has specific activity in the control of P. oryzae, similar to kasugamycin, a secondary metabolite of S. kasugaensis. However, much of the earlier work on mode of action was carried out using another antibiotic, cycloheximide. 

Blasticidin (52) is an antibiotic isolated from Streptomyces griseochro-mogenes in 1955 [87]. Detailed physicochemical properties were reported in 1968, but the structure remained undefined [88]. Interest in this metabolite was renewed recently with the isolation of the homologous compounds aflastatin A and B (53, 54), metabolites of S. griseochro-... 

With the structures of aflastatin A (53) and B (N-demethyl aflastatin A, 54) secured, the structure of the related blasticidin A (52) was determined in a similar manner. Studies on the biosynthesis of aflastatin A... 

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