Studies on a Novel Serine Protease of a DhapADprtV Vibrio cholerae O1 Strain and Its Role in Hemorrhagic Response in the Rabbit Ileal Loop Model
IR@IICB: CSIR-Indian Institute of Chemical Biology, KolkataView Archive Info
Studies on a Novel Serine Protease of a DhapADprtV
Vibrio cholerae O1 Strain and Its Role in Hemorrhagic
Response in the Rabbit Ileal Loop Model
Rompikuntal, Pramod K
Dhira Rani, Saha
Chakrabarti, Manoj K
Bhadra, Rupak K
Wai, Sun Nyunt
Infectious Diseases and Immunology
Background: Two well-characterized proteases secreted by Vibrio cholerae O1 strains are hemagglutinin protease (HAP) and
V. cholerae protease (PrtV). The hapA and prtV knock out mutant, V. cholerae O1 strain CHA6.8DprtV, still retains residual
protease activity. We initiated this study to characterize the protease present in CHA6.8DprtV strain and study its role in
pathogenesis in rabbit ileal loop model (RIL).
Methodology/Principal Findings: We partially purified the residual protease secreted by strain CHA6.8DprtV from culture
supernatant by anion-exchange chromatography. The major protein band in native PAGE was identified by MS peptide
mapping and sequence analysis showed homology with a 59-kDa trypsin-like serine protease encoded by VC1649. The
protease activity was partially inhibited by 25 mM PMSF and 10 mM EDTA and completely inhibited by EDTA and PMSF
together. RIL assay with culture supernatants of strains C6709 (FA ratio 1.1+/20.3 n = 3), CHA6.8 (FA ratio 1.08+/20.2 n = 3),
CHA6.8DprtV (FA ratio 1.02+/20.2 n = 3) and partially purified serine protease from CHA6.8DprtV (FA ratio 1.2+/20.3 n = 3)
induced fluid accumulation and histopathological studies on rabbit ileum showed destruction of the villus structure with
hemorrhage in all layers of the mucosa. RIL assay with culture supernatant of CHA6.8DprtVDVC1649 strain (FA ratio 0.11+/
20.005 n = 3) and with protease incubated with PMSF and EDTA (FA ratio 0.3+/20.05 n = 3) induced a significantly reduced
FA ratio with almost complete normal villus structure.
Conclusion: Our results show the presence of a novel 59-kDa serine protease in a DhapADprtV V. cholerae O1 strain and its
role in hemorrhagic response in RIL model.
Syngkon, Aurelia and Elluri, Sridhar and Koley, Hemanta and Rompikuntal, Pramod K and Dhira Rani, Saha and Chakrabarti, Manoj K and Bhadra, Rupak K and Wai, Sun Nyunt and Pal, Amit (2010) Studies on a Novel Serine Protease of a DhapADprtV Vibrio cholerae O1 Strain and Its Role in Hemorrhagic Response in the Rabbit Ileal Loop Model. PLOS ONE, 5 (9).