Structure modeling and antidiabetic activity of a seed protein of Momordica charantia in non-obese diabetic (NOD) mice

Momordica charantia is a well known medicinal plant used in the traditional medicinal system for the treatment of various diseasesincluding diabetes mellitus. Recently, a novel protein termed as ADMc1 from the seed extract of M. charantia has been identifiedand isolated showing significant antihyperglycemic activity in type 1 diabetic rats in which diabetes was induced. However, thestructure of this protein has not yet been analyzed. Homology modeling approach was used to generate a high quality protein 3Dstructure for the amino acid sequence of the ADMc1 protein in this study. The comparative assessment of secondary structuresrevealed ADMc1 as an all-alpha helix protein with random coils. Tertiary structure predicted on the template structure of Napin ofB. Napus (PDB ID: 1SM7) with which the ADMc1 showed significant sequence similarity, was validated using protein structurevalidation tools like PROCHECK, WHAT_CHECK, VERIFY3D and ProSA. Arrangement of disulfide bridges formed by cysteineresidues were predicted by the Dianna 1.1 server. The presence of multiple disulfide bond confers the stable nature of the ADMc1protein. Further, the biological activity of the ADMc1 was assessed in non-obese diabetic (NOD) mice which are spontaneousmodel of type 1 diabetes. Significant reduction in the blood glucose levels of NOD mice was observed up to 8 h post administrationof the rADMc1 protein. Overall, the structural characterizations with antihyperglycemic activity of this seed protein of Momordicacharantia demonstrate its potential as an antidiabetic agent.