Glycogen Synthase Kinase 3/antagonists & inhibitors; Protein Isoforms/antagonists & inhibitors; Protein Kinase Inhibitors/pharmacology; Recombinant Proteins/antagonists & inhibitors; Amino Acid Motifs/drug effects; Binding Sites; Crystallography, X-Ray; Escherichia coli; Gene Expression; Glycogen Synthase Kinase 3/chemistry; Glycogen Synthase Kinase 3/genetics; Glycogen Synthase Kinase 3/metabolism; Humans; Kinetics; Leishmania infantum/drug effects; Leishmania infantum/genetics; Leishmania infantum/metabolism; Leishmania major/drug effects; Leishmania major/genetics; Leishmania major/metabolism; Leishmaniasis, Cutaneous/drug therapy; Leishmaniasis, Cutaneous/genetics; Leishmaniasis, Cutaneous/metabolism; Leishmaniasis, Visceral/drug therapy; Leishmaniasis, Visceral/genetics; Leishmaniasis, Visceral/metabolism; Models, Molecular; Mutation; Protein Binding/drug effects; Protein Isoforms/chemistry; Protein Isoforms/genetics; Protein Isoforms/metabolism; Protein Kinase Inhibitors/therapeutic use; Recombinant Proteins/chemistry; Recombinant Proteins/genetics; Recombinant Proteins/metabolism; Species Specificity; Structure-Activity Relationship; Trypanosoma brucei brucei/drug effects; Trypanosoma brucei brucei/genetics; Trypanosoma brucei brucei/metabolism