Dr. S. S. Indi
Ph.D (Exeter University)
Phone: +91 80 22932885
My expertise lies in electron micrography and in collaboration with several scientists on campus I have tried to unravel the ultrastructural details of microscopic specimen.
Studies on Hyper Rayleigh Scattering (HPS) of copper nano particles
Copper nano particles were prepared by laser ablation of pure copper or copper oxide using Q switched Nd:YAG laser. The HPS measurements were done using Nd:YAG laser. The incoherent second harmonic light scattered from solution were collected. Electron microscopy of copper particles was done by loading 10 ul sample on carbon coated grids and the sizes were measured. The first hyperpolarization value scale quadratically with particle size which implies the 2 harmonic responses from copper nano particles result from symmetry breaking at the surface of the particle rather than in the bulk (This was done in collaboration with Prof P K Das of Inorganic &Physical Chemistry department).
Studies on two important neurological diseases,
Alpha synuclein filaments are the main components of inclusion bodies in Parkinson disease (PD). Metals are significant factors in PD and their interaction with alpha synuclein affect the kinetics of fibrillation. Transmission electron microscopy was used to monitor the aggregation of synuclein. These studies showed that while in wild type Cu (II) induced thin long network of fibrils, in mutants amorphous aggregates were formed. On the other hand Fe(III) induced short thick fibrils in both cases. Thus alpha synuclein exhibits metal specific fibril formation.
Alzheimer’s disease is characterized by deposition of amyloid plaques. Garlic is known to reduce plaque formation. The aqueous garlic extract not only inhibited the plaque formation but also defibrillate preformed fibrils. Incubation for three days showed maximum defibrillation by TEM. This study suggests that consumption of garlic may lead to inhibition of A beta aggregation in human brain (This was carried out in collaboration with Dr. K. S. J. Rao of Central Food Technology Research Institute Mysore).
Studies on liposomes as gene delivery system
In this study 15 novel dimeric and three monomeric lipids anchored on an aromatic backbone were designed synthesized and their gene delivery efficacy was studied. Using two different cell lines HeLa and HT 1080, the gene delivery efficacy of various lipids of different chain and spacer length was investigated. Both the cell types showed preference to lipids of different chain lengths. The lipoplexes were formed by mixing different lipids and DNA in defined quantities and observed. Electron microscopy showed existence of spherical lipid DNA complexes (This was done along with Prof. S Bhattacharya of Organic Chemistry department)
Studies on cell division protein FtsZ
Structure-function aspects of bacterial homologue of tubulin, a molecule called FtsZ have been studied. Polymerization properties of FtsZ between various species of bacteria and between various deletion and point mutations of Mycobacterial FtsZ are being investigated. Electron microscope is used to visualize FtsZ polymers. The salient finding of our research includes discovery of first wild type FtsZ (Mycobacterium leprae FtsZ) that does not polymerize under standard condition in vitro. Further it is shown that a single residue at position 172 increases polymerization drastically(This was done in collaboration with Prof P Ajitkumar of this department).
Indi, S., Wakley, G., Stebbings, H (1985) Does freeze-substituion reveal the hydrophobic nature of interprotofilament bonding in microtubules? Cell Biol Int Rep 9, 859
Maitra, U., Mukhopadhyay, S., Sarkar,A., Rao,P., Indi S ( 2001) Hydrophobic pockets in a nonpolymeric aqueous gel: Observation of such a gelation process by color change Angewandte Chemie 40, 2281.
Gupta, P., Srinivasan, R., Rajeswari, H., Indi, S., Ajitkumar, P. (2008) In vitro polymerization of Mycobacterium leprae FtsZ OR Mycobacterium tuberculosis FtsZ is revived or abolished, respectively, by reciprocal mutation of a single residue Biochem Biophys.Res Comm 368, 445.
Chandra, M. Indi, S S., Das, P K (2007) Depolarized hyper-Rayleigh scattering from copper nanoparticles J Phys Chem C 111, 10652.
Bharathi, Indi, S S., Rao, K S J (2007) Copper- and iron-induced differential fibril formation in α-synuclein: TEM study. Neuroscience Lett 424, 78.