TIFR
Department of Chemical Sciences
School of Natural Sciences

April 22, 2019 at 4.00 pm in AG-69

Title :

Predicting directional flexibility of protein from its crystal structure

Abstract :

Mechanical flexibility is found to be anisotropic in protein molecules. In order to understand complex role of protein in mechano-biology or develop new allosteric protein based nano-materials, anisotropic response of protein to uniaxial mechanical stress is needed to be understood in detail. In this talk I will propose an analytical framework to compute directional flexibility in terms of directional spring constant of proteins from its native state crystal structure. Our formalism includes Cα atom based coarse-grained Elastic Network Model (ENM) where we employed statistical propagation of error to obtain variance of a distance between two atoms from standard deviation of coordinates of the constituent atoms using ENM normal modes. Directional flexibility of Ubiquitin predicted in this way is almost ~ 70% accurate in comparison to that obtained from all atom explicit solvent Molecular Dynamics simulation. I will also discuss about tuning ENM potential to get better agreement on directional flexibility prediction. 

April 25, 2019 at 4.00 pm in AG-80

Title :

Fluorescent Red Emitting Sensors for Imaging Signal Mediating Phospholipids

April 30, 2019 at 2.30 pm in AG-69

Title :

Advancement of Nanomaterials: Nanotherapeutics and Antibacterial Performance

Abstract :

       Carbon nanomaterials are promising in nature due to their higher surface area, known chemistry and ease of structural functionalization. A higher surface area and modulation of functionalities is the key to success to extend their potential in various domains. Present chemistry of graphene oxide (GO) synthesis is dominated by Hummer’s method and its modified versions. The non-reproducibility, variation in sources and physical reaction parameters affect size, degree of oxidation, nature, and type of oxo-functionalities. Furthermore, problems associated with its mass production demands development of better and easier synthetic protocols. In our lab, we are exploring safer, easier, less-energy intensive protocols for synthesis of GO and their advancement in biomedical applications.

       Nanotherapeutics is most appealing and viable approach to enhance the potential of existing drugs rather than designing and synthesizing new drug molecules to counter diseases. More recently, gene-based antitumor therapy demands smart engineering of effective vectors.

In this respect, we have explored biocompatible polymers tethered GO nanoconjugates as efficient nonviral vectors for gene-based cancer therapeutics. A promisable transfection and gene-knock down efficiency is revealed and results were compared with commercial vector. A pH-triggered release of siRNA from the vector-siRNA complex was studied to provide a mechanistic insight toward unloading of siRNA from the vector.

       In another work, enhancement in efficacy of traditional medicine with non-toxic surface modified metal oxide nanoparticles is explored. The nanoparticles are specially designed to allow sustained release of bound species to facilitate prolonged activity of drug.

 

       Additionally, pristine GO coatings synthesized from different routes revealed remarkable antimicrobial activity due to its specific surface-interface interactions with the bacteria, which is again a valuable addition at biomedical frontiers.

 

April 18, 2019 at 4.00 pm in AG-80

Title :

Amorphous Zeolitic Nanosponges as Heterogeneous Solid Catalysts

May 1, 2019 at 2.30 pm in AG-69

Title :

Buoyant Microcapsules: Simple motility to Complex Autonomous Behavior

Abstract :

Nature has always been a great source of inspiration for the design of artificial materials with improved hierarchical organization, superior properties and smart functions. In this age of artificial intelligence and smart systems, chemists are increasingly looking to design active and adaptive materials taking inspiration from the various biological processes and their self-regulatory mechanisms which make ‘life’ possible. In this talk, I will illustrate with an example of a microcapsule with an entrapped gas bubble whose motility is governed by buoyancy forces, how we can design complex autonomous behavior into relatively simple systems. Our results show that microcapsules can be propelled by an active control of buoyancy forces and this buoyant motility can be used to trigger chemical reactions, simulate self-sorting behavior in microcapsule communities and achieve complex oscillatory motility.

References:

  1. B. A. Grzybowski & W. T. S. Huck, The Nanotechnology of Life-inspired Systems, Nat. Nanotechnol. 2016, 11, 585.
  2. B. V. V. S. P. Kumar, A. J. Patil & S. Mann, Enzyme-powered motility in buoyant organoclay/DNA protocells, Nat. Chem. 2018, 10, 1154.
  3. L. Rodriguez-Arco, B. V. V. S. P. Kumar, M. Li, A. J. Patil & S. Mann, Modulation of Higher-order Behaviour in Model Protocell Communities by Artificial Phagocytosis, Angew. Chem. Int. Ed. 2019, DOI: 10.1002/ange.201901469.