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Purification, Characterization and Inhibition of Alanine Racemase from a Pathogenic Strain of Streptococcus iniae

Streptococcus iniae is a pathogenic and zoonotic bacteria that impacted high mortality to many fish species as well as capable of causing serious disease to humans. Alanine racemase (Alr, EC 5.1.1.1) is a pyridoxal-5’-phosphate (PLP)-containing homodimeric enzyme that catalyzes the racemization of L...

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Autores principales: MUHAMMAD, MURTALA, LI, YANGYANG, GONG, SIYU, SHI, YANMIN, JU, JIANSONG, ZHAO, BAOHUA, LIU, DONG
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Exeley Inc. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7256847/
https://www.ncbi.nlm.nih.gov/pubmed/31880879
http://dx.doi.org/10.33073/pjm-2019-036
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author MUHAMMAD, MURTALA
LI, YANGYANG
GONG, SIYU
SHI, YANMIN
JU, JIANSONG
ZHAO, BAOHUA
LIU, DONG
author_facet MUHAMMAD, MURTALA
LI, YANGYANG
GONG, SIYU
SHI, YANMIN
JU, JIANSONG
ZHAO, BAOHUA
LIU, DONG
author_sort MUHAMMAD, MURTALA
collection PubMed
description Streptococcus iniae is a pathogenic and zoonotic bacteria that impacted high mortality to many fish species as well as capable of causing serious disease to humans. Alanine racemase (Alr, EC 5.1.1.1) is a pyridoxal-5’-phosphate (PLP)-containing homodimeric enzyme that catalyzes the racemization of L-alanine and D-alanine. In this study, we purified alanine racemase from S. iniae that was isolated from an infected Chinese sturgeon (Acipenser sinensis), as well as determined its biochemical characteristics and inhibitors. The alr gene has an open reading frame (ORF) of 1107 bp, encoding a protein of 369 amino acids, which has a molecular mass of 40 kDa. The enzyme has optimal activity at a temperature of 35°C and a pH of 9.5. It belongs to the PLP-dependent enzymes family and is highly specific to L-alanine. S. iniae Alr (SiAlr) could be inhibited by some metal ions, hydroxylamine and dithiothreitol (DTT). The kinetic parameters K(m) and V(max) of the enzyme were 33.11 mM, 2426 units/mg for L-alanine, and 14.36 mM, 963.6 units/mg for D-alanine. Finally, the 50% inhibitory concentrations (IC(50)) values and antibiotic activity of two alanine racemase inhibitors (homogentisic acid and hydroquinone), were determined and found to be effective against both Gram-positive and Gram-negative bacteria employed in this study.
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spelling pubmed-72568472020-06-03 Purification, Characterization and Inhibition of Alanine Racemase from a Pathogenic Strain of Streptococcus iniae MUHAMMAD, MURTALA LI, YANGYANG GONG, SIYU SHI, YANMIN JU, JIANSONG ZHAO, BAOHUA LIU, DONG Pol J Microbiol Microbiology Streptococcus iniae is a pathogenic and zoonotic bacteria that impacted high mortality to many fish species as well as capable of causing serious disease to humans. Alanine racemase (Alr, EC 5.1.1.1) is a pyridoxal-5’-phosphate (PLP)-containing homodimeric enzyme that catalyzes the racemization of L-alanine and D-alanine. In this study, we purified alanine racemase from S. iniae that was isolated from an infected Chinese sturgeon (Acipenser sinensis), as well as determined its biochemical characteristics and inhibitors. The alr gene has an open reading frame (ORF) of 1107 bp, encoding a protein of 369 amino acids, which has a molecular mass of 40 kDa. The enzyme has optimal activity at a temperature of 35°C and a pH of 9.5. It belongs to the PLP-dependent enzymes family and is highly specific to L-alanine. S. iniae Alr (SiAlr) could be inhibited by some metal ions, hydroxylamine and dithiothreitol (DTT). The kinetic parameters K(m) and V(max) of the enzyme were 33.11 mM, 2426 units/mg for L-alanine, and 14.36 mM, 963.6 units/mg for D-alanine. Finally, the 50% inhibitory concentrations (IC(50)) values and antibiotic activity of two alanine racemase inhibitors (homogentisic acid and hydroquinone), were determined and found to be effective against both Gram-positive and Gram-negative bacteria employed in this study. Exeley Inc. 2019-09 2019-09-03 /pmc/articles/PMC7256847/ /pubmed/31880879 http://dx.doi.org/10.33073/pjm-2019-036 Text en © 2019 Murtala Muhammad et al. https://creativecommons.org/licenses/by-nc-nd/4.0/ https://creativecommons.org/licenses/by-nc-nd/4.0/This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License (https://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Microbiology
MUHAMMAD, MURTALA
LI, YANGYANG
GONG, SIYU
SHI, YANMIN
JU, JIANSONG
ZHAO, BAOHUA
LIU, DONG
Purification, Characterization and Inhibition of Alanine Racemase from a Pathogenic Strain of Streptococcus iniae
title Purification, Characterization and Inhibition of Alanine Racemase from a Pathogenic Strain of Streptococcus iniae
title_full Purification, Characterization and Inhibition of Alanine Racemase from a Pathogenic Strain of Streptococcus iniae
title_fullStr Purification, Characterization and Inhibition of Alanine Racemase from a Pathogenic Strain of Streptococcus iniae
title_full_unstemmed Purification, Characterization and Inhibition of Alanine Racemase from a Pathogenic Strain of Streptococcus iniae
title_short Purification, Characterization and Inhibition of Alanine Racemase from a Pathogenic Strain of Streptococcus iniae
title_sort purification, characterization and inhibition of alanine racemase from a pathogenic strain of streptococcus iniae
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7256847/
https://www.ncbi.nlm.nih.gov/pubmed/31880879
http://dx.doi.org/10.33073/pjm-2019-036
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