title: Novel protein-protein interaction between spermidine synthase and S-adenosylmethionine decarboxylase from Leishmania donovani.
abstract: Polyamine biosynthesis pathway has long been considered an essential drug target for trypanosomatids including Leishmania. S-adenosylmethionine decarboxylase (AdoMetDc) and spermidine synthase (SpdSyn) are enzymes of this pathway that catalyze successive steps, with the product of the former, decarboxylated S-adenosylmethionine (dcSAM), acting as an aminopropyl donor for the latter enzyme. Here we have explored the possibility of and identified the protein-protein interaction between SpdSyn and AdoMetDc. The protein-protein interaction has been identified using GST pull down assay. Isothermal titration calorimetry reveals that the interaction is thermodynamically favorable. Fluorescence spectroscopy studies also confirms the interaction, with SpdSyn exhibiting a change in tertiary structure with increasing concentrations of AdoMetDc. Size exclusion chromatography suggests the presence of the complex as a hetero-oligomer. Taken together, these results suggest that the enzymes indeed form a heteromer. Computational analyses suggest that this complex differs significantly from the corresponding human complex, implying that this complex could be a better therapeutic target than the individual enzymes.
authors.affiliation: Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, U.P., India.
authors.forename: Arjun K
authors.initials: AK
authors.lastname: Mishra
authors.affiliation: Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, U.P., India.
authors.forename: Pragati
authors.initials: P
authors.lastname: Agnihotri
authors.affiliation: Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, U.P., India.
authors.forename: Vijay Kumar
authors.initials: VK
authors.lastname: Srivastava
authors.affiliation: Molecular and Structural Biology Division, CSIR-Central Drug Research Institute, B.S. 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, U.P., India. Electronic address: jvpratap@cdri.res.in.
authors.forename: J Venkatesh
authors.initials: JV
authors.lastname: Pratap
mesh_terms: D012437:Adenosylmethionine Decarboxylase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015317:Biogenic Polyamines / Q000096:biosynthesis; D002151:Calorimetry; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D007893:Leishmania donovani / Q000201:enzymology*; D008856:Microscopy, Fluorescence; D025941:Protein Interaction Mapping; D015800:Protozoan Proteins / Q000737:chemistry* / Q000378:metabolism; D011436:Spermidine Synthase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D015317:Biogenic Polyamines; D015800:Protozoan Proteins; D011436:Spermidine Synthase; D012437:Adenosylmethionine Decarboxylase
keywords: Leishmania; Metabolon; Polyamine; S-adenosylmethionine decarboxylase; Spermidine synthase