title: Functional characterization of Helicobacter pylori TlyA: pore-forming hemolytic activity and cytotoxic property of the protein.
abstract: Helicobacter pylori is a human specific gastric pathogen. H. pylori pathogenesis process involves a number of well-studied virulence factors that include the 'vacuolating cytotoxin' and the 'cytotoxin associated gene A'. Analysis of the H. pylori genome, however, indicates presence of additional virulence factors that are yet to be characterized in molecular detail. For example, H. pylori genome harbors a gene that has potential to encode a protein with sequence similarity to those of the TlyA-like proteins of several pathogenic bacteria. Earlier studies have indicated potential association of this H. pylori tlyA gene in the virulence mechanism of the organism. Despite such notions, however, the TlyA-like protein of H. pylori has not been studied previously in molecular detail. In particular, purified form of H. pylori TlyA has never been studied before toward exploring its functional properties. Here, we report characterization of the H. pylori TlyA protein purified from the recombinant over-expression system in Escherichia coli. Purified form of the recombinant TlyA exhibits prominent hemolytic activity against human erythrocytes, presumably via formation of pores of specific diameter in the cell membrane. Purified TlyA also triggers prominent cytotoxic responses in human gastric adenocarcinoma cells. Altogether, our study establishes H. pylori TlyA as a potential virulence factor of the organism.
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Manauli, 140306 Punjab, India.
authors.forename: Kusum
authors.initials: K
authors.lastname: Lata
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Manauli, 140306 Punjab, India.
authors.forename: Karan
authors.initials: K
authors.lastname: Paul
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, SAS Nagar, Manauli, 140306 Punjab, India. Electronic address: kausik@iisermohali.ac.in.
authors.forename: Kausik
authors.initials: K
authors.lastname: Chattopadhyay
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D002942:Circular Dichroism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000187:drug effects; D004926:Escherichia coli / Q000235:genetics; D016480:Helicobacter pylori / Q000235:genetics / Q000378:metabolism; D006460:Hemolysin Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D006460:Hemolysin Proteins; D011994:Recombinant Proteins; C588092:TlyA protein, Helicobacter pylori; D037521:Virulence Factors
keywords: Bacterial toxin; Cytotoxin; Helicobacter pylori; Hemolysin; TlyA