Proteins composed of peptides play a very important role in human life. Peptides complex with metals to perform various functions such as enzyme catalysts, oxygen carriers and anti tumor agents etc., Of all metals, transition metal copper complex was considered an area of interest because of its wide pharmaceutical applications and less toxicity. Characterization of these complexes using various crystallographic, spectral and thermal techniques gives a better view of the binding, interactions and few physical properties.
Crystal structure studies through X-ray crystallography, spectral studies by Fluorescence, UV-Vis and NMR in addition to thermal properties by DSC were determined. Crystals of Ser-Glu dipeptide by itself were obtained and analyzed with X-ray crystallography. Binding of copper metal to dipeptide was estimated by using Fluorescence & UV-Vis spectroscopies and NMR studies, while melting point temperature of dipeptides was determined by solid state DSC. Results from the spectral studies showed that binding was possible with a transition metal like Cu2+ but lack of packing energy or stability resulted in failure of crystallization of these complexes. Spectral studies also contributed to the revelation of possible binding sites on the dipeptides, which help in altering the confirmation of dipeptides that aid in novel drug design, by increasing stability and bioavailability and by decreasing the side effects. All these determinations followed by other techniques like stability test, dissolution test along with other pharmacological activity tests can be used to develop a better drug delivery system.