Investigation of bioluminescence-based assays for determination of kinetic parameters for the bifunctional Neisseria meningitidis serogroup W capsule polymerase.

Laleh Sheikhi Moghaddam, Ayobami Adegbite, Pumtiwitt C McCarthy

BMC research notes 2021 Nov 18

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Neisseria meningitidis is a Gram-negative bacterium that causes meningitis. N. meningitidis serogroup W (NmW) capsule polymerase synthesizes capsular polysaccharide of this serogroup. This enzyme could be a tool for meningococcal glycoconjugate vaccine development. Our long-term goal is to control activity of the NmW capsule polymerase for production of defined carbohydrates for vaccines. The enzyme lacks a simple, high-throughput activity assay. Here, we describe the use of high-throughput bioluminescence assays (CMP-Glo and UDP-Glo by Promega) to investigate NmW capsule polymerase activity. These assays detect free nucleotides produced during transfer of sugar from UDP-Galactose and CMP-Sialic Acid to an acceptor. Kinetic studies using NmW hydrolyzed polysaccharide (PS) acceptor are described as well as preliminary work with a sialic acid trimer (DP3) acceptor. In CMP-Glo kinetic studies, with constant donor (80 µM) and varied NmW hydrolyzed polysaccharide (0-2000 µg/mL), a Km of 629.2 ± 101.4 µg/mL and a Vmax of 0.8965 ± 0.05823 µM/min was obtained. Using UDP-Glo, Km and Vmax values of 13.84 ± 9.675 µM and 0.6205 ± 0.1331 µM/min were obtained with varied CMP-NeuNAc (0-80 µM) and constant acceptor (400 µg/mL) and UDP-Gal (80 µM). This is the first report of using bioluminescence assays for NmW kinetics. © 2021. The Author(s).

Citation

Laleh Sheikhi Moghaddam, Ayobami Adegbite, Pumtiwitt C McCarthy. Investigation of bioluminescence-based assays for determination of kinetic parameters for the bifunctional Neisseria meningitidis serogroup W capsule polymerase. BMC research notes. 2021 Nov 18;14(1):417