Identification, purification, and characterization of a secretory serine protease in an Indian strain of Leishmania donovani

Autor: Tapati Chakraborti, Tripti De, Rajdeep Choudhury, Siddhartha Kumar Bhaumik
Rok vydání: 2008
Předmět:
Zdroj: Molecular and Cellular Biochemistry. 320:1-14
ISSN: 1573-4919
0300-8177
DOI: 10.1007/s11010-008-9849-7
Popis: An aprotinin sensitive serine protease was identified in the culture supernatant of the Indian strain of Leishmania donovani (MHOM/IN/1983/AG83). The protease was subsequently purified and characterized. The apparent molecular mass of the enzyme was 115 kDa in SDS-PAGE under non-reducing condition, while on reduction it showed a 56 kDa protein band indicating that the protease is a dimeric protein. The purified enzyme was optimally active at the pH and temperature of 7.5 and 28 degrees C, respectively. Assays of thermal stability indicated that the enzyme preserved 59% of activity even after pretreatment at 42 degrees C for 1 h. The purified protease was not glycosylated and its isoelectric pI was 5.0. N-alpha-p-tosyl-L-arginine methylester (TAME) appeared to be relatively better substrate among the commonly used synthetic substrates. The enzyme was inhibited by Ca(2+) and Mn(2+), but activated by Zn(2+). The protease could play important role(s) in the pathogenesis of visceral leishmaniasis or kala-azar.
Databáze: OpenAIRE
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