Screening for Type II L-Asparaginases: Lessons from the Genus Halomonas

Authors

  • Mahmood Barati Department of Pharmaceutical Biotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  • Mohammadreza Khoshayand Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
  • Sina Adrangi Department of Pharmaceutical Biotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  • Zeinab Sharafi Department of Pharmaceutical Biotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Abstract:

Among the two types of bacterial L-asparaginases, only type II enzymes have been used inthe treatment of acute lymphoblastic leukemia owing to their higher affinity for L-asparagine.However, current screening media used for the isolation of L-asparaginase-producingmicroorganisms do not discriminate between the two types of L-asparaginase. During anoptimization study conducted to increase L-asparaginase production by environmentalHalomonas isolates, it was noticed that the pattern of L-asparaginase production in responseto variations in glucose concentration varied between different isolates suggesting that theydiffer in their ability to produce type II L-asparaginases, an observation that was confirmed byfurther experiments. Bioinformatics analysis of available Halomonas whole genome sequencesrevealed that indeed some species of this genus possess both L-asparaginase types while otherspossess only type I enzymes. By comparing the growth pattern of these isolates on differentmedia, we propose that by omitting glucose, reducing the concentration of L-asparagine andproviding an alternative nitrogen source in L-asparaginase screening media it may be possibleto differentiate between type I and type II activities.

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Journal title

volume 16  issue 4

pages  1565- 1573

publication date 2017-11-01

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