TY - JOUR
T1 - Structural and Mechanistic Insights into Mycobacterium abscessus Aspartate Decarboxylase PanD and a Pyrazinoic Acid-Derived Inhibitor
AU - Saw, Wuan Geok
AU - Leow, Chen Yen
AU - Harikishore, Amaravadhi
AU - Shin, Joon
AU - Cole, Malcolm S.
AU - Aragaw, Wassihun Wedajo
AU - Ragunathan, Priya
AU - Hegde, Pooja
AU - Aldrich, Courtney C.
AU - Dick, Thomas
AU - Grüber, Gerhard
N1 - Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/7/8
Y1 - 2022/7/8
N2 - Mycobacterium tuberculosis (Mtb) aspartate decarboxylase PanD is required for biosynthesis of the essential cofactor coenzyme A and targeted by the first line drug pyrazinamide (PZA). PZA is a prodrug that is converted by a bacterial amidase into its bioactive form pyrazinoic acid (POA). Employing structure-function analyses we previously identified POA-based inhibitors of Mtb PanD showing much improved inhibitory activity against the enzyme. Here, we performed the first structure-function studies on PanD encoded by the nontuberculous mycobacterial lung pathogen Mycobacterium abscessus (Mab), shedding light on the differences and similarities of Mab and Mtb PanD. Solution X-ray scattering data provided the solution structure of the entire tetrameric Mab PanD, which in comparison to the structure of the derived C-terminal truncated Mab PanD1-114mutant revealed the orientation of the four flexible C-termini relative to the catalytic core. Enzymatic studies of Mab PanD1-114explored the essentiality of the C-terminus for catalysis. A library of recombinant Mab PanD mutants based on structural information and PZA/POA resistant PanD mutations in Mtb illuminated critical residues involved in the substrate tunnel and enzymatic activity. Using our library of POA analogues, we identified (3-(1-naphthamido)pyrazine-2-carboxylic acid) (analogue 2) as the first potent inhibitor of Mab PanD. The inhibitor shows mainly electrostatic- and hydrogen bonding interaction with the target enzyme as explored by isothermal titration calorimetry and confirmed by docking studies. The observed unfavorable entropy indicates that significant conformational changes are involved in the binding process of analogue 2 to Mab PanD. In contrast to PZA and POA, which are whole-cell inactive, analogue 2 exerts appreciable antibacterial activity against the three subspecies of Mab.
AB - Mycobacterium tuberculosis (Mtb) aspartate decarboxylase PanD is required for biosynthesis of the essential cofactor coenzyme A and targeted by the first line drug pyrazinamide (PZA). PZA is a prodrug that is converted by a bacterial amidase into its bioactive form pyrazinoic acid (POA). Employing structure-function analyses we previously identified POA-based inhibitors of Mtb PanD showing much improved inhibitory activity against the enzyme. Here, we performed the first structure-function studies on PanD encoded by the nontuberculous mycobacterial lung pathogen Mycobacterium abscessus (Mab), shedding light on the differences and similarities of Mab and Mtb PanD. Solution X-ray scattering data provided the solution structure of the entire tetrameric Mab PanD, which in comparison to the structure of the derived C-terminal truncated Mab PanD1-114mutant revealed the orientation of the four flexible C-termini relative to the catalytic core. Enzymatic studies of Mab PanD1-114explored the essentiality of the C-terminus for catalysis. A library of recombinant Mab PanD mutants based on structural information and PZA/POA resistant PanD mutations in Mtb illuminated critical residues involved in the substrate tunnel and enzymatic activity. Using our library of POA analogues, we identified (3-(1-naphthamido)pyrazine-2-carboxylic acid) (analogue 2) as the first potent inhibitor of Mab PanD. The inhibitor shows mainly electrostatic- and hydrogen bonding interaction with the target enzyme as explored by isothermal titration calorimetry and confirmed by docking studies. The observed unfavorable entropy indicates that significant conformational changes are involved in the binding process of analogue 2 to Mab PanD. In contrast to PZA and POA, which are whole-cell inactive, analogue 2 exerts appreciable antibacterial activity against the three subspecies of Mab.
KW - Mycobacterium abscessus
KW - aspartate decarboxylase
KW - coenzyme A
KW - nontuberculous mycobacteria
KW - pyrazinamide
KW - pyrazinoic acid
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U2 - 10.1021/acsinfecdis.2c00133
DO - 10.1021/acsinfecdis.2c00133
M3 - Article
C2 - 35731701
AN - SCOPUS:85134361255
SN - 2373-8227
VL - 8
SP - 1324
EP - 1335
JO - ACS Infectious Diseases
JF - ACS Infectious Diseases
IS - 7
ER -