TY - JOUR
T1 - Structural Characterization of Neisseria gonorrhoeae Bacterial Peroxidase—Insights into the Catalytic Cycle of Bacterial Peroxidases
AU - Nóbrega, Cláudia S.
AU - Carvalho, Ana Luísa
AU - Romão, Maria João
AU - Pauleta, Sofia R.
N1 - info:eu-repo/grantAgreement/FCT/Concurso para Projectos de I&D em todos os Domínios Científicos - 2009/PTDC%2FBIA-PRO%2F109796%2F2009/PT#
info:eu-repo/grantAgreement/FCT/Concurso para Financiamento de Projetos de Investigação Científica e Desenvolvimento Tecnológico em Todos os Domínios Científicos - 2017/PTDC%2FBIA-BQM%2F29442%2F2017/PT#
info:eu-repo/grantAgreement/FCT/Projectos de IC&DT de Consolidação de Competências e Recursos em Investigação - 2012/RECI%2FBBB-BEP%2F0124%2F2012/PT#
info:eu-repo/grantAgreement/FCT/OE/SFRH%2FBD%2F87878%2F2012/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDP%2F04378%2F2020/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F04378%2F2020/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/LA%2FP%2F0140%2F2020/PT#
Acknowledgments
The authors would like to thank Lina Juknaité for her contribution in the initial crystallization studies. The authors acknowledge the European Synchrotron Radiation Facility and the Swiss Light Source for provision of synchrotron radiation facilities and access to beamlines BM30 and PXIII (X06DA), respectively.
PY - 2023/3/26
Y1 - 2023/3/26
N2 - Neisseria gonorrhoeae is an obligate human pathogenic bacterium responsible for gonorrhea, a sexually transmitted disease. The bacterial peroxidase, an enzyme present in the periplasm of this bacterium, detoxifies the cells against hydrogen peroxide and constitutes one of the primary defenses against exogenous and endogenous oxidative stress in this organism. The 38 kDa heterologously produced bacterial peroxidase was crystallized in the mixed-valence state, the active state, at pH 6.0, and the crystals were soaked with azide, producing the first azide-inhibited structure of this family of enzymes. The enzyme binds exogenous ligands such as cyanide and azide, which also inhibit the catalytic activity by coordinating the P heme iron, the active site, and competing with its substrate, hydrogen peroxide. The inhibition constants were estimated to be 0.4 ± 0.1 µM and 41 ± 5 mM for cyanide and azide, respectively. Imidazole also binds and inhibits the enzyme in a more complex mechanism by binding to P and E hemes, which changes the reduction potential of the latest heme. Based on the structures now reported, the catalytic cycle of bacterial peroxidases is revisited. The inhibition studies and the crystal structure of the inhibited enzyme comprise the first platform to search and develop inhibitors that target this enzyme as a possible new strategy against N. gonorrhoeae.
AB - Neisseria gonorrhoeae is an obligate human pathogenic bacterium responsible for gonorrhea, a sexually transmitted disease. The bacterial peroxidase, an enzyme present in the periplasm of this bacterium, detoxifies the cells against hydrogen peroxide and constitutes one of the primary defenses against exogenous and endogenous oxidative stress in this organism. The 38 kDa heterologously produced bacterial peroxidase was crystallized in the mixed-valence state, the active state, at pH 6.0, and the crystals were soaked with azide, producing the first azide-inhibited structure of this family of enzymes. The enzyme binds exogenous ligands such as cyanide and azide, which also inhibit the catalytic activity by coordinating the P heme iron, the active site, and competing with its substrate, hydrogen peroxide. The inhibition constants were estimated to be 0.4 ± 0.1 µM and 41 ± 5 mM for cyanide and azide, respectively. Imidazole also binds and inhibits the enzyme in a more complex mechanism by binding to P and E hemes, which changes the reduction potential of the latest heme. Based on the structures now reported, the catalytic cycle of bacterial peroxidases is revisited. The inhibition studies and the crystal structure of the inhibited enzyme comprise the first platform to search and develop inhibitors that target this enzyme as a possible new strategy against N. gonorrhoeae.
KW - Bacterial peroxidase
KW - pathogenic bacteria
KW - Neisseria gonorrhoeae
KW - inhibition
U2 - 10.3390/ijms24076246
DO - 10.3390/ijms24076246
M3 - Article
SN - 1422-0067
VL - 24
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 7
M1 - 6246
ER -