Removal of histidine residue from ZN-α-2-glycoprotein by carboxypeptidase enzyme using spectrofluorimetry and MALDI-TOF-Mass spectroscopy

Abstract

The present invention relates, in general, to methods developed of diagnosing and monitoring to binding with Zn-α-2-glycoprotein in order to design rational drugs. Zinc-alpha-2-glycoprotein (ZAG) is a secreted protein that is present in most bodily fluids. It is interesting because of its ability to play many important functions in the human body, including fertilization and lipid mobilization. After the discovery of this molecule, during the last 5 decades, various studies have been documented on its structure and functions but still it is considered as a protein with an unknown function. Its expression is regulated by glucocorticoids. Due to its high sequence homology with lipid-mobilizing factor and high expression in cancer cachexia, it is considered as a novel adipokine. On the other hand, its X-ray crystal structure and folding structure is similar to MHC class I antigen-presenting molecule; hence ZAG may have a role in the expression of the immune response and providing defined binding-altered mutants for cellular signaling studies and potential medical application. Spectrofluorimetry and MALDI-TOF Mass Spectroscopy showed that ZAG binds DAUDA with Kdin the micro molar range. This study will examine removal of histidine residue from recombinant ZAG protein by enzymes through Spectrofluorimetry and MALDI-TOF Mass Spectroscopy.