​Among several methods and techniques, such as x-ray crystallography and NMR, Raman spectroscopic approach is currently becoming a very unique and useful tool in modern biology. It aids significantly to understand the structure function relationship of complicated biological systems. Recent great evolution in Raman instrumentation and sample preparation procedures have vastly improved the sensitivity and selectivity of Raman spectroscopy as a probe of proteins, nucleic acids, and their complexes. Raman approaches are now feasible to probe structure and dynamics of small or large protein molecule and supramolecular assemblies such as viruses and amyloid aggregates linked to several neurological disorder. With an appropriate experimental design and suitable spectroscopic assignments we can investigate orientations of molecular subgroups in drug receptor interactions and the nature and strength of hydrogen-bonding in biomolecular recognition and enzyme function. It also able to provide the kinetic and thermodynamic parameters that govern structural transformations in biological assemblies. If a microscope is coupled to the Raman spectrometer we can derive information of protein oligomers or a living cell and microorganisms. The Raman method also can provide molecular blueprint, nature and orientation of proteins in its crystalline form and can monitor chemical events inside protein crystal and living cells in a very short time intervals. The method has also unique potential to define the optical and morphological behavior of nano-biomaterials and their conjugate with different type of antibodies. We started biological Raman and FT IR laboratory to probe biological molecules and events in crystal, semi-solid, and inside living cell. Using a Raman microscope, it is possible to obtain protein Raman spectroscopic data of high quality. We plan to probe events ranging from small cooperative conformational changes to massive and unexpected secondary structural changes in the protein in different assembly structure.
It is assumed and supported that a well defined 3D protein structure is pre-requisite for its function and cellular activity. However, many proteins or segments of it intrinsically disordered (ID). It is estimated that about 50% of human proteins contain at least one long (> 30 residues) intrinsically disorder regions (IDR) and the number of IDR containing proteins is more in higher eukaryotes. Thus, it may have evolutionary importance. The IDPs (intrinsically disorder proteins) lack any well-defined three dimensional folded structures in solution and structurally they remain as an ensemble of interconverting conformations under physiological conditions. The lack of a rigid and folded stable structure may provide large plasticity to IDPs to interact efficiently with different targets, and aid good efficacy in cell cycle regulation, membrane transport and different molecular recognition processes. In addition the inherited structural disorder and the hydrophobic patches in it play an important role in the formation of protein assembly structure and the production of amyloid like aggregates that is implicated in several human neurological disorders.
Using several experimental methods we study peptides (amyloid beta), proteins (insulin, alpha synuclein, lysozyme and NS3 protease), and other biomolecules. We are especially interested to know behaviour of protein oligomers and the early detection of the Alzheimer’s and Parkinson disease state. Disordered regions in globular proteins and their partial unfolding, and unstable structural domain in disordered protein play significant role in oligomer formation and our effort is to define these states by Raman and NMR spectroscopy.
We inclined to provide a description of the protein disorder in different solution conditions, backbone conformation of the protein when it forms assembly structure, chaperone function of IDPs and disorder regions on other proteins and viec-versa, link of IDPs to cancer, IDPs in plant proteins. Further, we attempt to define the role of this class of proteins in cell signalling and their implication in neurological disorder. Also develop spectroscopic method that could aid in developing methods for the early detection of Alzheimer’s and Parkinson disease based on Raman spectroscopy.
Molecular interaction inside single protein crystal. Understanding of protein interactions with small molecules is of a major interest as it provides greater understanding of protein function and also it provides methods to develop therapeutic intervention. Raman spectroscopy allow us to obtain the Raman spectrum of very good quality We plan to probe (i) hydration and dynamics of the side chain residues of the protein itself and (ii) small molecule interaction with the protein in their crystalline form. In addition we want to see in real time how the protein and other macromolecules interact with each other and form membrane less organelles. This structure has significant role in cell signaling and neuro-transmittance and we, by systematic Raman analysis our aim is to derive detail structural information of these species.
Current cancer treatments are mainly based on radiation and chemotherapeutic agents, which has several side effects including severe damage to epithelial surfaces, infertility, swelling of soft tissues, and other side effects.1 Multidrug-resistance (MDR) is another primary limitation to the success of chemotherapy. Several reports suggested that nanoparticles, particularly from gold, could be a choice that has the strong potential to deliver drug inside cancer cells. With surface modification nanoparticles found to achieve enhanced permeability and retention of drug molecules and be preferentially localized to tumors sites with high concentration level and thus enhanced drug effect. we developed tetrasodium salt of meso-tetrakis(4-sulfonatophenyl)porphyrin modified gold nanoparticles (TPPS-AuNPs) that efficiently delivers the loaded doxorubicin molecule within the nucleus of tumor cells and thereby improved the therapeutic efficacy of the drug. We are making more effiecient porphrin based nano system for their better use in cancer therapy.
In our investigation, water soluble tetrasodium salt of meso-tetrakis (4-sulphonatophenyl)-porphyrin (TPPS) was adjoined with gold nanosurface and the composite showed strong efficiency to bind with doxorubicin and can effectively release the drug molecules inside cancer cells. Our results established that TPPS-AuNPs can significantly reduce the dose of doxorubicin and thereby showed improved efficacy towards killing of brain cancer cells which is a challenging task due to the fast development and poor prognosis of this tumor.
