Molecular cloning and characterization of cathepsin-L cysteine protease gene of Toxocara canis

The present study was carried out to characterize cathepsin-L cysteine protease gene of Toxocara canis for future utilization as a diagnostic molecule or as a drug target. Total RNA was extracted from intact adult worms and reverse transcription was done with oligo dT primers to obtain complementary DNA (cDNA). PCR was carried out using cDNA as template with specific primers which amplified a product of 1082 bp. The amplicon was cloned into pDrive cloning vector and clone was confirmed by restriction enzyme analysis. The sequence homology revealed 99% and 97.8% respectively at nucleotide and amino acid level with published T. canis cathepsin-L cysteine protease gene (accession no: U53172 AY). Structural analysis shown that the mature cathepsin-L protein consist of 360 amino acids with a molecular weight of 41475.82 Daltons. Further expression studies are required for producing the recombinant protein for its evaluation in the diagnosis of T. canis infection in humans as well as in adult dogs.