In silico evaluation of Lipl32 peptides for antigen candidates in leptospirosis diagnostic

Abstract

Leptospirosis is a zoonotic infectious disease caused by the spirochete of the genus Leptospira. The gold-standard technique for diagnosis is the microscopic agglutina tion test, however, this serological test is complex and time consuming, and requires specific equipment, highly trained staff, and the live cultures of reference strains of Leptospira for use as antigens. It is for this reason that the search for antigenic can didates for immunodiagnostics takes on significant importance. LipL32 is an outer membrane lipoprotein that is exclusively found in pathogenic leptospires, highly con served and immunogenic. In this study, in silico analysis of the amino acid sequence of LipL32 was carried out with the aim of finding peptides that are good candidates for diagnostic use, bound to gold nanoparticles. First, amino acid sequences of lipL32 were searched in Genbank and conservation in pathogenic leptospires (Pomona and Hardjo) was compared between them, using the MUSCLE clustal platform. The signal peptide region was determined by DTU health tech as it is ruled out as an anti gen. Remaining amino acid sequence was evaluated in different predictors of epi topes (EMBOSS, Antibody Epitope Prediction, SVMTrip, Predicted Antigenic Peptides, ABC Pred). Once the results of the predictors were obtained, they were compared with each other. The peptides that matched in most of the predictors were selected and evaluated with PepCalc for molecular weight and water solubility.