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Immunolocalization and Characterization of Two Novel Proteases in Leishmania Donovani: Putative Roles in Host Invasion and Parasite Development

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Title Immunolocalization and Characterization of Two Novel Proteases in Leishmania Donovani: Putative Roles in Host Invasion and Parasite Development
 
Creator Choudhury, Rajdeep
Das, Partha
De, Tripti
Chakraborti, Tapati
 
Subject Infectious Diseases and Immunology
 
Description Two novel intracellular proteases having identical molecular mass (58 kDa) were purified from virulent
Indian strain of Leishmania donovani by a combination of aprotinin-agarose affinity chromatography,
ion exchange chromatography and finally continuous elution electrophoresis. Both of these proteases
migrate in SDS-PAGE as a single homogeneous bands suggesting monomeric nature of these proteases.
The enzyme activity of one of the proteases was inhibited by serine protease inhibitor aprotinin and
another one was inhibited by metalloprotease inhibitor 1, 10 phenanthroline. The purified enzymes were
thus of serine protease (SP-Ld) and metalloprotease (MP-Ld) type. The optimal pH for protease activity is
8.0 and 7.5 for SP-Ld and MP-Ld respectively. The temperature optimum for SP-Ld is 28 �C and for MP-Ld
is 37 �C showing their thermostability upto 60 �C. Broad substrate (both natural and synthetic) specificity
and the effect of Ca2þ upon these enzymes suggested novelty of these proteases. Kinetic data indicate
that SP-Ld is of trypsin like as BAPNA appears to be the best substrate and MP-Ld seems to be collagenase
type as it degrades azocoll with maximum efficiency. Both immunofluorescence and immune-gold
electron microscopy studies revealed that the SP-Ld is localized in the flagellar pocket as well as at the
surface of the parasite, whereas MP-Ld is located extensively near the flagellar pocket region. This work
also suggests that the uses of anti SP-Ld and anti MP-Ld antibodies are quite significant in interfering
with the process of parasite invasion and multiplication respectively. Thus the major role of SP-Ld could
be predicted in invasion process as it down regulates the phagocytic activity of macrophages, and MP-Ld
appears to play important roles in parasitic development.
 
Date 2010
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://www.eprints.iicb.res.in/974/1/17_Biochimie_2010.pdf
Choudhury, Rajdeep and Das, Partha and De, Tripti and Chakraborti, Tapati (2010) Immunolocalization and Characterization of Two Novel Proteases in Leishmania Donovani: Putative Roles in Host Invasion and Parasite Development. Biochimie, 92 (10). pp. 1274-1286.
 
Relation http://dx.doi.org/10.1016/j.biochi.2010.05.015
http://www.eprints.iicb.res.in/974/