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.com
Volume 9
Journal of Biotechnology & Biomaterials
ISSN: 2155-952X
JOINT EVENT
February 28-March 02, 2019 | Berlin, Germany
5
th
International Conference on
Enzymology and Protein Chemistry
&
22
nd
Global Congress on
Biotechnology
Biotechnology 2019
Enzymology 2019
February 28-March 02, 2019
&
Bioprospecting and rational engineering of newL-asparaginase to present a better biopharmaceutical
for blood cancer treatment
Tales A Costa-Silva
1
, I M Costa
1
, G S Agamez-Montalvo
2
, A Pessoa
1
and
G Monteiro
1
1
University of Sao Paulo, Brazil
2
Federal University of Ceara, Brazil
L
-asparaginase (E.C.3.5.1.1) produced by bacteria is used in the treatment of acute lymphocytic leukemia (ALL). However,
innumerable side effects were registered by the usage of bacterial L-ASNase during ALL treatment. Other drawbacks
associated with prokaryotic L-asparaginase treatment are hypersensitivity reactions, low thermal stability, human proteases
degradation and rapid clearance. Some techniques have been used to overcome these downsides such as bioprospecting
eukaryotic sources or modification of commercial bacterial L-asparaginases by site-directed mutagenesis. In order to find
eukaryotic sources of L-ASNase, 20 filamentous fungi were used in this study, which were isolated from the microbiome of the
jellyfish Olindias sambaquiensis. Six fungi samples isolated from jellyfish tentacles (brown structures in jelly fish responsible to
toxin production) showed L-asparaginase production by submerged fermentation process. The highest activity was shown by
Strain OS02 with 2.7 U/g. This strain was selected for optimization of L-asparaginase production by central composite design
of response surface methodology. For maximum enzyme production (11.45 U/g), the best condition was modified Czapek–
Dox medium supplemented with L-asparagine and adjusted to pH 7.4 at 32.5 °C and 190 rpm. Regarding protein engineering
of commercial bacterial L-asparaginases we used site-directed mutagenesis to obtain L-asparaginase protease-resistance: a
new Escherichia coli L-asparaginase (EcAII) variant, triple mutant. The preliminary results showed that mutant enzyme was
expressed in E. coli BL21 (DE3) and preserved original L-asparaginase activity. These L-asparaginases proteoforms may be
alternative biopharmaceuticals with the potential of further improving outcome in ALL treatment.
Biography
Tales A Costa-Silva has completed his Graduation in Biological Sciences at Federal University of Alfenas, Brazil and is pursuing his PhD at Sao Paulo University,
Brazil. He has experience in Microbiology, focusing on Industrial Microbiology, acting on the following subjects: Industrial Enzymology (Production, Purification,
Immobilization, Characterization and Application) and Pharmaceutical Biotechnology.
talesmilleto@yahoo.com.brTales A Costa-Silva et al., J Biotechnol Biomater 2019, Volume 9
DOI: 10.4172/2155-952X-C2-116