A genetic polymorphism study of a gene encoding lipase from Helicobacter pylori strains isolated in vietnam

Nguyen Mai Khanh, Pham Thi Vinh Hoa, Vo Thi Thuong, Pham Bao Yen

Abstract


Our study showed that lipase plays an important role in lipid hydrolysis of gastric mucosa, helping Helicobacter pylori bacteria attach and penetrate the stomach, causing gastric ulcer diseases that could develop into cancer. Lipase can be divided into two main groups including lipase (EC 3.1.1.3) and carboxylesterase (EC 3.1.1.1). Interestingly, there has been not much information about the subgroup lipase V, which belongs to the later. To study the polymorphism at the molecular level and to clone the gene coding for EstV, twenty-six H. pylori strains in Vietnam were isolated for DNA extraction and amplification using specifically designed primers and optimized thermal cycle. The expected PCR product had approximately 750 bp. The electrophoresis results showed a single band as expected without smear and unspecific bands. The PCR product was then sequenced and analyzed by comparison with the H. pylori 26695 strain. The polymorphism analysis showed that only one strain with high similarity with the reference strain (98% similarity in translated amino acid sequence). Specially, 14/26 strains had sequences with more than 3% differences (based on 97% cut off of polypeptide sequence). Interestingly, some strains show polymorphism in the highly conserved amino acid blocks, which could significantly affect the activity of enzyme as well as the survival of the microorganism. To identify the significance of nucleotide changes, the EstV coding gene will be inserted into a cloning vector and the activity of the expressed recombinant enzyme will be characterized.


Keywords


Helicobacter pylori, cloning lipase, EstV, polymorphism.

Full Text:

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DOI: https://doi.org/10.15625/0866-7160/v37n1se.6099 Display counter: Abstract : 83 views. Untitled : 158 views.

 

                 

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