{'fraction_non_alphanumeric': 0.046052631578947366, 'fraction_numerical': 0.03223684210526316, 'mean_word_length': 5.390756302521009, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Characterization and immunolocalization of inositol phosphorylceramide in Leishmania (Viannia) braziliensis

Leishmania ssp is a protozoan parasite responsible for cutaneous, mucocutaneous and visceral disease. Leishmania expresses a class of sphingolipids, inositol phosphorylceramides (IPC). Lipids of Leishmania (Viannia) braziliensis promastigotes were extracted and analyzed by electrospray ionization‐mass spectrometry by positive and negative ion modes to detect parental ions of inositol and sphingosines. IPC species were identified at m/z 752 (d32:0), m/z 778 (d34:1), m/z 780 (d34:0), m/z 806 (d36:1), m/z 808 (d36:0). IPC of L. braziliensis displays a prominent ion at m/z 778.4, and its structure determined as d20:1/14:0, differing from IPC (d16:1/18:0) isolated from L. major and L. amazonensis, thus suggesting expression of sphingosine synthases with different specificities, as serine steaoryltransferase for L. braziliensis, and serine myristoyltransferase for L. major and L. amazonensis. These results show that L. braziliensis expresses IPC with a longer sphingosine compared to other Leishmania species. Using a specific monoclonal antibody to IPC and confocal microscopy it was demonstrated that IPC is present in the inner leaflet membrane and may be involved in intracellular signaling. The absence of IPC in mammals and the presence of an unusual sphingosine (d20:1) suggest that L. braziliensis IPC may represent a potential target for new therapeutic drugs. Supported by FAPESP, CNPq, CAPES.