Serine protease activities in Leishmania (Leishmania) chagasi promastigotes

• Published in: Parasitology research (1987) Vol. 107; no. 5; pp. 1151 - 1162
• Main Authors: da Silva-López, Raquel Elisa, dos Santos, Tatiana Resende, Morgado-Díaz, José Andrés, Tanaka, Marcelo Neves, de Simone, Salvatore Giovanni
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.10.2010; Springer-Verlag; Springer
• Subjects: Animals; Antibodies, Protozoan - immunology; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cations, Divalent - metabolism; Coenzymes - metabolism; Enzyme Stability; Enzymes; Fundamental and applied biological sciences. Psychology; General aspects; General aspects and techniques. Study of several systematic groups. Models; Hemoglobins - metabolism; Hydrogen-Ion Concentration; Immunology; Invertebrates; Leishmania - enzymology; Leishmania amazonensis; Leishmania chagasi; Medical Microbiology; Microbiology; Microscopy, Fluorescence; Molecular Weight; Organelles - enzymology; Original Paper; Ovalbumin - metabolism; Protozoan Proteins - chemistry; Protozoan Proteins - isolation & purification; Protozoan Proteins - metabolism; Rabbits; Serine; Serine Proteases - chemistry; Serine Proteases - isolation & purification; Serine Proteases - metabolism; Serum Albumin, Bovine - metabolism; Substrate Specificity; Temperature; Thrombin; Serine Protease Activity; Chloromethyl Ketone; Serine Protease; Leishmaniasis; Visceral Leishmaniasis; Kinetoplastida; Protozoa; Leishmania chagasi; Serine; Parasite; Activity; Promastigote
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-010-1983-y

The present work reports the isolation, biochemical characterization, and subcellular location of serine proteases from aqueous, detergent soluble, and culture supernatant of Leishmania chagasi promastigote extracts, respectively, LCSII, LCSI, and LCSIII. The active enzyme molecular masses of LCSII were about 105, 66, and 60 kDa; of LCSI, 60 and 58 kDa; and of LCSIII, approximately 76 and 68 kDa. Optimal pH for the enzymes was 7.0 for LCSI and LCSIII and 8.5 for LCSII, and the optimal temperature for all enzymes was 37°C, using α-N-ρ-tosyl-l-arginine methyl ester as substrate. Assay of thermal stability indicated that LCSIII is the more stable enzyme. Hemoglobin, bovine serum albumin, and ovalbumin were hydrolyzed by LCSII and LCSI but not by LCSIII. Inhibition studies suggested that enzymes belong to the serine protease class modulated by divalent cations. Rabbit antiserum against 56-kDa serine protease of Leishmania amazonensis identified proteins in all extracts of L. chagasi. Furthermore, immunocytochemistry demonstrated that serine proteases are located in flagellar pocket region and cytoplasmic vesicles of L. chagasi promastigotes. These findings indicate that L. chagasi serine proteases differ from L. amazonensis proteases and all known flagellate proteases, but display some similarities with serine proteases from other Leishmania species, suggesting a conservation of this enzymatic activity in the genus.