Plants produce an array of peptides as part of their innate defense mechanism against pathogens. The potential use of these peptides for various therapeutic purposes is increasing per diem. In order to excel in this research, the community requires web repositories that provide reliable and accurate information about these phyto-peptides. This work is an attempt to bridge the gaps in plant-based peptide research. PlantPepDB is a manually curated database that consists of 3848 plant-derived peptides among which 2821 are experimentally validated at the protein level, 458 have experimental evidence at the transcript level, 530 are predicted and only 39 peptides are inferred from homology. Incorporation of physicochemical properties and tertiary structure into PlantPepDB will help the users to study the therapeutic potential of a peptide, thus, debuts as a powerful resource for therapeutic research. Different options like Simple, Advanced, PhysicoChem and AA composition search along with browsing utilities are provided in the database for the users to execute dynamic search and retrieve the desired data. Interestingly, many peptides that were considered to possess only a single property were found to exhibit multiple properties after careful curation and merging the duplicate data that was collected from published literature and already available databases. Overall, PlantPepDB is the first database comprising detailed analysis and comprehensive information of phyto-peptides from a broad functional range which will be useful for peptide-based applied research. PlantPepDB is freely available at http://www.nipgr.ac.in/PlantPepDB/.

Donepezil, a highly selective and reversible inhibitor, is amongst the widely used drugs for treatment of Alzheimer’s disease (AD) across the globe. Clinically significant human transferrin (hTf) is a key player involved in iron metabolism. The current study targets to have an insight into the interaction between donepezil and this plasma protein, hTf using UV-vis absorbance, fluorescence, isothermal titration calorimetry, circular dichroism and molecular docking techniques. UV spectroscopy of hTf in the presence of donepezil revealed the occurrence of hyperchromism coupled with blue shift in indicating complex formation. Binding constant obtained from UV-vis absorption measurements was of the order 0.9 x10⁴ M⁻¹ implicative of strong binding. Fluorescence spectroscopy shows that donepezil quenches fluorescence intensity of the native hTf in dynamic manner with a shift in wavelength maxima. Donepezil binds to hTf at 310 K with a binding constant of 1.3 X 10⁴ M⁻¹ suggestive of strong binding. ITC results clearly suggest the reaction to be spontaneous and thermodynamically favorable. CD spectroscopy also showed a shift in the spectrum of the native hTf in the presence of donepezil suggesting formation of complex between protein and drug. Further, molecular docking experiments showed Pro 91, Phe 94 and His 207 to be key players involved in the complex formation. This study gives an insight into the molecular basis of interaction between donepezil and hTf thereby aiding in understanding the activity and mechanism of protein and drug binding. This will serve as a boon for drug designing industries which are working day and night for improved treatment of existing disorders across the world.