Nuclear Magnetic resonance spectroscopy (NMR) is an analytical technique that is based on using the known chemical constituent of a compound to distinguish it from other unknown compounds. The ability of this technique to distinguish the difference in molecular structure of substances and the information it provides about the dynamics and interactions of molecule in the smallest possible unit of a matter makes it an indispensable tool in the process drug discovery, development and delivery. This chemical analytical method is very sensitive to its environment, so can give very minute information about how the smallest fragment of a molecule binds to a target molecule, protein or its complexes. Information about the exact binding site or interaction between the fragment and the receptor of interest is also highlighted. Hence, this technique is a very vital technique in the Pharmaceutical, forensic, quality control industry. This analytic technique also has its application in the field of research where it is used to determine the purity, quality, quantity and structure of the unknown while confirming that of the known substance. The combination of this analytical chemistry technique to Protein in the biological science is what is known as Protein NMR.
Protein Nuclear Magnetic Resonance has been used extensively to study enzyme mechanisms, analyzing structures of proteins, nucleic acid and its complexes This technique is also employed in studying protein-ligand /protein interactions and the dynamics of the protein. In the field of drug development, the study of protein and its complexes are of utmost importance as they play a vital role in physiological and pathological conditions and process hence the importance of thoroughly understanding their catalytic process and how they bind to their substrate. Protein NMR in active site mapping thus, is the application of NMR in the region of an enzyme where substrate molecules bind and undergo chemical reaction as well as where its residues form temporary chemical bonds with the substrate. This region in an enzyme is known as the active site. The mapping of active sites is quite crucial in the field of pharmaceutical science or drug discovery. The detailed knowledge of the site of a target receptor for drug discovery and the understanding of the protein dynamics in the targeted site will maximize the efficacy of the proposed drug by giving a clear and precise understanding of the protein-ligand binding information and protein-ligand/protein interaction (Yan Li et al,2017). These interactions aid the design of new drugs for instance enzyme inhibitors, by providing in-depth details of the size on the active sites, how many subsidies are present, their properties, how they come together and bind chemically. The understanding of this unique interaction is also a tool for comparison in active site mapping, where it is employed to compare protein active sites and their structures in more details so as to design drugs that can exactly match into the enzyme-substrate complex using the key and lock analog for enzymes.
This protein analytical tool has been used in lots of studies to investigate enzyme behaviors, their mechanisms as it takes less time an effort to acquire structural information of compounds and DNA when compared to other methods like X-ray crystallography, fluorescence and IR spectroscopy, hence the ever-growing importance of active site mapping using Protein NMR.(Yong et al.2012)
19FNMR studies has to be done to clearly distinguish structural and functional features of its recent application in active site mapping out of galactose binding- protein, transmembrane aspartate receptor, the Che – Y protein dihydrofolate reductase , elongation factor-TU, and D-lactose protein as seen in dehydrogenase, that demonstrate the utility of 19 F NMR in the analysis of protein conformation state even in particles that are so large or unstable for full NMR structure determination.(Mark A.D, et al 2010).These kinds of studies depend on the chemical shift pattern of FNMR as this method is very sensitive to change in its environment due to the presence of fluorine 19, as well as the existing weak Vander Waal force of bond as well as the presence of the local electrostatic field.