An Insight into the Constitutive Proteome Throughout Leishmania donovani Promastigote Growth and Differentiation.

Anthroponotic visceral leishmaniasis is a life-threatening disease caused by Leishmania donovani (Kinetoplastida: Trypanosomatidae) in East Africa and the Indian subcontinent. Unlike promastigote growth and differentiation in the sand fly gut or in axenic culture, L. donovani promastigote-into-amastigote development has been studied by high-throughput gene expression profiling. In this study, we have identified abundant constitutive proteins in axenically cultured promastigotes by two-dimension electrophoresis and matrix-assisted laser desorption-ionization tandem time-of-flight (MALDI-TOF/TOF) mass spectrometry. Most proteins involved in the trypanothione-based redox antioxidant system are expressed constitutively throughout axenic L. donovani promastigote growth and differentiation (tryparedoxin, trypanothione peroxidase, generic peroxidoxin, iron-superoxide dismutase, and elongation factor 1β). These findings are in agreement with previous data on other Old World species (i.e., L. major and L. infantum), whereas New World species (i.e., L. amazonensis and L. pifanoi) and Crithidia fasciculata show different expression patterns.