Disease relevance of Ascamycin

• Purification and characterization of ascamycin-hydrolysing aminopeptidase from Xanthomonas citri [1].
• Mechanism of action and selective toxicity of ascamycin, a nucleoside antibiotic [2].
• An unidentified Streptomyces sp. produces two nucleoside antibiotics, ascamycin and its dealanyl derivative [2].
• When ascamycin was dealanylated, dealanylascamycin showed a broad antibacterial activity against various Gram-negative and Gram-positive bacteria [1].
• Both ascamycin and dealanylascamycin inhibited the protein synthesis of X. citri, but only dealanylascamycin inhibited that of Escherichia coli [2].

High impact information on Ascamycin

• Isolation and characterization of the gene encoding an aminopeptidase involved in the selective toxicity of ascamycin toward Xanthomonas campestris pv. citri [3].
• The XAP gene product, Xap, expressed in Escherichia coli has proline iminopeptidase activity as well as ascamycin dealanylating activity in vitro [3].
• 7. The enzyme catalysed the hydrolysis of the alanyl group of ascamycin and liberated alanine from the sulphamoyl nucleoside [1].
• It is suggested that ascamycin cannot be transported through mammalian cell membranes but dealanylascamycin can permeate; a similar situation exists in prokaryotic cells [4].
• An ascamycin dealanylating enzyme (Xc-aminopeptidase) has been isolated from Xanthomonas citri and characterized as a proline iminopeptidase of molecular weight of 38,000 (H. OSADA & K. ISONO, Biochem. J. 233: 459 approximately 463, 1986) [4].

Anatomical context of Ascamycin

• Occurrence of an ascamycin dealanylating enzyme, Xc-aminopeptidase, in mammalian cell membranes and susceptibility to ascamycin [4].

References