Uses
Virginiamycin complex is defined as a mixture of 75% ostreogrycin A (virginamycin M1) and 25% virginiamycin S1, together with the less abundant S analogues. As the two major components have quite different solubilities, these proportions are not readily achieved or used. BioAustralis has isolated and re-combined the individual components to provide the defined components of virginiamycin complex. The composition of the complex is important as Virginiamycin S1 acts a synergist, binding to the conformational change of the peptidyl transferase centre of the 50S ribosome induced by ostreogrycin A.
Uses
Virginiamycin S1 is one of a family of depsipeptide antibiotics co-produced with ostreogrycin A and used as a synergistic mixture. Virginiamycin S1, also known as Staphylomycin S and Factor S among other synonyms, was discovered independently and named by several groups, leading to considerable confusion in the literature. Virginiamycin S1 acts a synergist, binding to the conformational change of the peptidyl transferase centre of the 50S ribosome induced by ostreogrycin A. Virginiamycin S1 differs from virginiamycin B in lacking the dimethylamino moiety on the phenyl ring.
Biological Activity
virginiamycin s1 is a macrolide antibiotic that reversibly inhibits protein synthesis [1][2][3].virginiamycin complex contains two antibiotics, virginiamycin m1 and virginiamycin s1. streptogramins are divided into class a and class b based on their structures. virginiamycin s1 is a member of the streptogramin b group of antibiotics, which bind the peptide exit tunnel to inhibit the elongation stage of translation. they show good bactericidal activity against methicillin-resistant s. aureus (mrsa), although resistance in mrsa is conferred by the cfr gene. virginiamycin m1 has activity against gram-positive and in select cases gram-negative bacteria. combination of group a and b streptogramins exhibit bactericidal activity [1]. virginiamycin s1 acted synergistically with virginiamycin m1 to irreversibly inhibit protein synthesis in bacteria. in cell-free systems, virginiamycin m1 and virginiamycin s1 bound to the large ribosomal subunit, and the affinity of ribosomes for vs is increased by vm [2][3].
References
[1]. fair rj, tor y. antibiotics and bacterial resistance in the 21st century. perspect medicin chem. 2014 aug 28;6:25-64.
[2]. kehrenberg c, cuny c, strommenger b, et al. methicillin-resistant and -susceptible staphylococcus aureus strains of clonal lineages st398 and st9 from swine carry the multidrug resistance gene cfr. antimicrob agents chemother. 2009 feb;53(2):779-81.
[3]. parfait r, cocito c. lasting damage to bacterial ribosomes by reversibly bound virginiamycin m. proc natl acad sci u s a. 1980 sep;77(9):5492-6.
