Abstract
Lactobacillus fructosus requires nicotinamide for growth and maintenance. The biosynthetic pathway of nicotinamide adenine dinucleotide (NAD) in this microorganism shows that the microorganism contains a phosphoribosyltransferase and an NAD pyrophosphorylase that are specific for nicotinamide and nicotinamide mononucleotide (NMN), respectively. This chapter discusses the assay method, purification procedure, and properties of nicotinamide phosphoribosyltransferase and NAD pyrophosphorylase from Lactobacillus fructosus . The activity of nicotinamide phosphoribosyltransferase is assayed by measuring the formation of NMN- 14 C from nicotinamide- 14 C in the presence of 5-phosphoribosyl-l-pyrophosphate (PRPP) and adenosine triphosphate (ATP). The ribonucleotide produced is isolated by paper chromatography and the radioactivity is determined. Enzyme activity may be assayed by measuring the formation of radioactive NAD from NMN- 14 C and ATP. The activity may be assayed in larger-scale incubation with higher concentrations of nonradioactive NMN, ATP, and the enzyme preparation. The NAD produced is determined by measuring the increase in absorbance at 340 m μ upon the addition of alcohol and alcohol dehydrogenase. The enzyme is specific for NMN and does not react with nicotinic acid ribonucleotide. The final preparation is practically free of nicotinamide phosphoribosyltransferase.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.