advances-in-protein-chemistry

advantages in characterizing the vibrational spectra and secondary structural affinity of native unfolded proteins. Raman spectra can be
achieved in dilute aqueous solution, a good feature that is of enhanced significance in characterizing natively unfolded proteins because
of their inclination to aggregate at higher concentrations. Moreover, Raman spectra permit the environment of several amino acid side
chains to be characterized, including the acidic residues, sulfur-containing residues and aromatic amino acids in different physical states.
Dual Polarization Interferometry (DPI)
Dual polarization interferometery is greatly sensitive analytical methodology employed for the determination of structure, function
as well as orientation of biological and other layers at solid-liquid interface, providing the measures of multiple parameters of molecules
at a surface showing information associating with packing and thickness related to layer refractive index (RI), stoichiomety (mass),
surface loading and density. DPI has been employed to investigate multiple types of phospholipids. Moreover, peptides relating to plasma
membrane like duramycin and V4 (antimicrobial peptide) and Melitti (component of bee venom) have been scrutinized (interaction
between meittin-lipid) by DPI. Mass and structural changes, in various proteins due to the function of metal ion concentration, including
Ca 2+ in calmodulin, prion containing Fe 2+ , β-amyloid associated with Cu 2+ etc have been studied by DPI [29]. DPI methodology has also
been employed for evaluating immobilization approach for DNA sensing surface and is challenging because of high charge on DNA
backbone rendering reachable orientation of molecule hard to accomplish [30,31].
Crystallographic analysis
As mentioned in the section of “Introduction”, x-ray crystallography is a type of high resolution microscopy which facilitates the
researchers to scrutinize the protein structures at the protein level and enhances the insight into protein functionality. As far function is
concerned, interaction of protein with other molecules, process of catalysis in case of enzymes and changes in conformational alteration
and studied during x-ray crystallographic analysis.
Figure 11: Use of Crystallography in Protein Structure and Function Determination.
In all types of microscopy, the detail and/or resolution depends upon the wavelength (λ) of the electromagnetic radiation used. Light
microscopy (λ= ~300nm) shows individual cells and its components (sub-cellular organelles). On contrary, electron microscopy (λ=