TY - JOUR
T1 - A HR-MS based method for the determination of chorismate synthase activity
AU - Khera, Harvinder K.
AU - Singh, Susheel K.
AU - Mir, Rafia
AU - Bharadwaj, Vikram
AU - Singh, Subhash
PY - 2017
Y1 - 2017
N2 - Chorismate synthase (Cs) catalyzes the last step of Shikimate pathway involving a unique biochemical reaction of anti-1,4 elimination of 3-phosphate group and the C-(6proR) hydrogen from 5-enolpyruvylshikimate-3-phosphate (EPSP) leading to the formation of chorismate, which is the common precursor for aromatic amino acid, ubiquinone, and folate biosynthesis in plants and several bacterial, fungal, and parasitic pathogens. Absence of Shikimate pathway in the vertebrate host, make Cs an appealing target for drug discovery against these pathogens. Here, we report a new method for detection of chorismate through a specific liquid chromatography, coupled with negative electrospray ionization high-resolution tandem mass spectrometry (ESI-HRMS) for determination of Cs enzyme activity. For this, we used a coupled enzyme reaction consisting of purified recombinant MtbEPSPs (EPSP synthase from Mycobacterium tuberculosis) for biosynthesis of EPSP, which is the substrate for Chorismate synthase along with MtbCs (Chorismate synthase both from Mycobacterium tuberculosis) for the formation of chorismate, followed by its detection through LC/HRMS. Since, the reaction components of Cs enzyme activity assay which otherwise may interfere with the other known spectrophotometric methods of checking Cs enzyme activity have no effect on this LC/HRMS based method, this method offer advantages over other existing methods for detection of Cs activity. Further, this LC/HRMS based method could be applicable for detection of enzyme activity of both monofunctional and bifunctional Cs from different species irrespective of their specific requirements of anaerobic or aerobic reaction conditions.
AB - Chorismate synthase (Cs) catalyzes the last step of Shikimate pathway involving a unique biochemical reaction of anti-1,4 elimination of 3-phosphate group and the C-(6proR) hydrogen from 5-enolpyruvylshikimate-3-phosphate (EPSP) leading to the formation of chorismate, which is the common precursor for aromatic amino acid, ubiquinone, and folate biosynthesis in plants and several bacterial, fungal, and parasitic pathogens. Absence of Shikimate pathway in the vertebrate host, make Cs an appealing target for drug discovery against these pathogens. Here, we report a new method for detection of chorismate through a specific liquid chromatography, coupled with negative electrospray ionization high-resolution tandem mass spectrometry (ESI-HRMS) for determination of Cs enzyme activity. For this, we used a coupled enzyme reaction consisting of purified recombinant MtbEPSPs (EPSP synthase from Mycobacterium tuberculosis) for biosynthesis of EPSP, which is the substrate for Chorismate synthase along with MtbCs (Chorismate synthase both from Mycobacterium tuberculosis) for the formation of chorismate, followed by its detection through LC/HRMS. Since, the reaction components of Cs enzyme activity assay which otherwise may interfere with the other known spectrophotometric methods of checking Cs enzyme activity have no effect on this LC/HRMS based method, this method offer advantages over other existing methods for detection of Cs activity. Further, this LC/HRMS based method could be applicable for detection of enzyme activity of both monofunctional and bifunctional Cs from different species irrespective of their specific requirements of anaerobic or aerobic reaction conditions.
KW - 5-enolpyruvylshikimate-3-phosphate
KW - Chorismate synthase
KW - Drug discovery
KW - Enzyme activity
KW - Mass spectrometry
KW - Mycobacterium tuberculosis
KW - Shikimate pathway
U2 - 10.2174/0929866523666161222153707
DO - 10.2174/0929866523666161222153707
M3 - Journal article
C2 - 28017143
AN - SCOPUS:85012005467
SN - 0929-8665
VL - 24
SP - 229
EP - 234
JO - Protein and Peptide Letters
JF - Protein and Peptide Letters
IS - 3
ER -
