Purification and partial characterization of NAD aminohydrolase from Aspergillus oryzae NRRL447

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• 作者：Thanaa H. Ali (1)
  Nadia H. Ali (2)
  Bakry M. Haroun (3)
  Amir E. Tantawy (1)
  
• 关键词：NAD aminohydrolase ; Aspergillus oryzae ; NAD degradation
• 刊名：World Journal of Microbiology and Biotechnology
• 出版年：2014
• 出版时间：March 2014
• 年：2014
• 卷：30
• 期：3
• 页码：819-825
• 全文大小：326 KB
• 作者单位：Thanaa H. Ali (1)
  Nadia H. Ali (2)
  Bakry M. Haroun (3)
  Amir E. Tantawy (1)
  
  1. Department of Microbial Chemistry, National Research Centre, Dokki, Cairo, Egypt
  2. Department of Biology, AD Darb Faculty of Science and Arts, Jazan University, Jazan, KSA
  3. Department of Microbiology, Al-Azhar University, Cairo, Egypt
  
• ISSN：1573-0972

文摘

Aspergillus oryzae aminohydrolase free acid phosphodiesterase catalyzes nicotinamide adenine dinucleotide to deamino-NAD and ammonia. The enzyme was purified to homogeneity by a combination of acetone precipitation, anion exchange chromatography and gel filtration chromatography. The enzyme was purified 230.5 fold. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme showed a single protein band of MW 94?kDa. The enzyme displayed maximum activity at pH 5 and 40?°C with NAD as substrate. The enzyme activity appeared to be stable up to 40?°C. The enzyme activity was enhanced slightly by addition of Na+ and K+, whereas inhibited strongly by addition of Ag+, Mn2+, Hg2+ and Cu2+ to the reaction mixtures. The enzyme hydrolyzes several substrates, suggesting a probable non-specific nature. The enzyme catalyzes the hydrolytic cleavage of amino group of NAD, adenosine, AMP, CMP, GMP, adenosine, cytidine and cytosine to the corresponding nucleotides, nucleosides or bases and ammonia. The substrate concentration–activity relationship is the hyperbolic type and the apparent Km and Kcat for the tested substrates were calculated.