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Enzymatic synthesis of 2′-deoxyuridine by whole cell catalyst co-expressing uridine phosphorylase and thymidine phosphorylase through auto-induction system

Paper ID Volume ID Publish Year Pages File Format Full-Text
20502 43177 2014 5 PDF Available
Title
Enzymatic synthesis of 2′-deoxyuridine by whole cell catalyst co-expressing uridine phosphorylase and thymidine phosphorylase through auto-induction system
Abstract

Genes encoding uridine phosphorylase (UP) and thymidine phosphorylase (TP) from Escherichia coli K12 were cloned and recombined respectively into plasmids pET-21a(+) and pET-28a(+). The recombinant plasmids BL21/pET21a-UP and BL21/pET28a-TP were co-transformed into E. coli BL21(DE3) to construct highly effective BTU strain (BL21/pET28a-TP, pET21a-UP) overexpressing both of UP and TP. BTU was cultivated in ZYM-Fe-5052 medium for 10 h and used as catalyst to synthesize 2′-deoxyuridine (dUR). It was found to increase the productivity of dUR by 8–9 fold when compared to wild E. coli K12 and E. coli BL21(DE3) strains. A series of experiments were carried out to find out the optimal conditions for synthesis of dUR. At 50°C, with 0.25‰ dry wt./v to catalyze the reaction of 2:1 β-thymidine: uracil (60 mM β-thymidine, 30 mM uracil), the conversion rate of dUR would reach 61.6% at 1 h, which was much higher than the rates obtained by BTU strain cultured in LB medium and induced by IPTG. This result proved co-expression and auto-induction were efficient methods in enhancing the expression quantity and activity of nucleoside phosphorylases, and they also had significant implications for large-scale industrial production of dUR and synthesis of other nucleoside derivatives.

Keywords
Biocatalysis; 2′-Deoxyuridine; Co-expression; Auto-induction; Nucleoside phosphorylase
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Enzymatic synthesis of 2′-deoxyuridine by whole cell catalyst co-expressing uridine phosphorylase and thymidine phosphorylase through auto-induction system
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Bioscience and Bioengineering - Volume 118, Issue 6, December 2014, Pages 723–727
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us