TY - JOUR
T1 - Characterization of d-boroAla as a novel broad-spectrum antibacterial agent targeting d-Ala-d-Ala ligase
AU - Putty, Sandeep
AU - Rai, Aman
AU - Jamindar, Darshan
AU - Pagano, Paul
AU - Quinn, Cheryl L.
AU - Mima, Takehiko
AU - Schweizer, Herbert P.
AU - Gutheil, William G.
PY - 2011/11
Y1 - 2011/11
N2 - d-boroAla was previously characterized as an inhibitor of bacterial alanine racemase and d-Ala-d-Ala ligase enzymes (Biochemistry, 28, 1989, 3541). In this study, d-boroAla was identified and characterized as an antibacterial agent. d-boroAla has activity against both Gram-positive and Gram-negative organisms, with minimal inhibitory concentrations down to 8μg/mL. A structure-function study on the alkyl side chain (NH 2-CHR-B(OR') 2) revealed that d-boroAla is the most effective agent in a series including boroGly, d-boroHomoAla, and d-boroVal. l-boroAla was much less active, and N-acetylation completely abolished activity. An LC-MS/MS assay was used to demonstrate that d-boroAla exerts its antibacterial activity by inhibition of d-Ala-d-Ala ligase. d-boroAla is bactericidal at 1× minimal inhibitory concentration against Staphylococcus aureus and Bacillus subtilis, which each encode one copy of d-Ala-d-Ala ligase, and at 4× minimal inhibitory concentration against Escherichia coli and Salmonella enterica serovar Typhimurium, which each encode two copies of d-Ala-d-Ala ligase. d-boroAla demonstrated a frequency of resistance of 8×10 -8 at 4× minimal inhibitory concentration in S. aureus. These results demonstrate that d-boroAla has promising antibacterial activity and could serve as the lead agent in a new class of d-Ala-d-Ala ligase targeted antibacterial agents. This study also demonstrates d-boroAla as a possible probe for d-Ala-d-Ala ligase function.
AB - d-boroAla was previously characterized as an inhibitor of bacterial alanine racemase and d-Ala-d-Ala ligase enzymes (Biochemistry, 28, 1989, 3541). In this study, d-boroAla was identified and characterized as an antibacterial agent. d-boroAla has activity against both Gram-positive and Gram-negative organisms, with minimal inhibitory concentrations down to 8μg/mL. A structure-function study on the alkyl side chain (NH 2-CHR-B(OR') 2) revealed that d-boroAla is the most effective agent in a series including boroGly, d-boroHomoAla, and d-boroVal. l-boroAla was much less active, and N-acetylation completely abolished activity. An LC-MS/MS assay was used to demonstrate that d-boroAla exerts its antibacterial activity by inhibition of d-Ala-d-Ala ligase. d-boroAla is bactericidal at 1× minimal inhibitory concentration against Staphylococcus aureus and Bacillus subtilis, which each encode one copy of d-Ala-d-Ala ligase, and at 4× minimal inhibitory concentration against Escherichia coli and Salmonella enterica serovar Typhimurium, which each encode two copies of d-Ala-d-Ala ligase. d-boroAla demonstrated a frequency of resistance of 8×10 -8 at 4× minimal inhibitory concentration in S. aureus. These results demonstrate that d-boroAla has promising antibacterial activity and could serve as the lead agent in a new class of d-Ala-d-Ala ligase targeted antibacterial agents. This study also demonstrates d-boroAla as a possible probe for d-Ala-d-Ala ligase function.
KW - Alanine branch
KW - Antibacterial
KW - Broad spectrum
KW - Cell wall
KW - d-Ala-d-Ala ligase
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U2 - 10.1111/j.1747-0285.2011.01210.x
DO - 10.1111/j.1747-0285.2011.01210.x
M3 - Article
C2 - 21827632
AN - SCOPUS:80054113900
SN - 1747-0277
VL - 78
SP - 757
EP - 763
JO - Chemical Biology and Drug Design
JF - Chemical Biology and Drug Design
IS - 5
ER -