Study On The Screening Of Matrix Gla Protein (MGP) Interacting Proteins

Kidney stones are common diseases in urology.The incidence rate is second only to urinary tract infections and prostatic diseases.It is the third most common morbidity in urology and has a high recurrence rate.The clinical manifestations are usually renal dysfunction and urinary tract obstruction.At present,the pharmacological mechanism of renal stone disease is still not clear yet.Some studies have shown that some of proteins are closely related to the formation of kidney stones and plays an important role in the formation of stones.The matrix γ-carboxyglutamate protein(MGP)is a vitamin K-dependent secretory protein consisting of multiple glutamic acid residues and is expressed in many tissues and organs in the human body.It has been confirmed that it plays an important role in the regulation of calcification of extracellular matrix,and it has been found to have inhibitory effects on vascular calcification and may be related to the interaction of bone morphogenetic protein-2(BMP-2).Some studies have found that MGP protein is also closely related to the formation of kidney stones,which may inhibit the formation of crystals,but the detail molecular mechanism is unknown yet.Systematic screening and study of MGPinteracting proteins can further elucidate its relationship with the formation of kidney stones and its detail molecular mechanisms.Therefore,the present study aimed to screen MGP interacting protein from human cDNA library by T7 phage display system and study possible interacting manner.First of all,we used pT7CFE1-NHis-GST-CHA as a vector to construct the MGP expression plasmid pT7CFE1-NHis-GST-CHA-MGP for mammalian eukaryotic expression system.A large number of human MGP proteins were obtained through protein in vitro expression system.Then,the MGP protein expressed in vitro was used as a bait protein and then the polypeptides interacting with MGP were screened using a human cDNA library T7 phage display system.The Phage ELISA method was further used to confirm the polypeptides.Toal 12 candidate interacting polupeptides including SLC27A6 were indentified.Finally,the structures of MGP protein and SLC27A6 were carried out by homology modeling and their interacting manner was studied by molecular dockingIn summary,we indentified 12 candidate proteins interacting with MGP utilizing T7 phage expression screening system and studied the possible interacting manner of MGP and SLC27A6 by molecular simulation.Our results laid the foundation for the further study on the molecular mechanism of MGP in the kidney stone formation and may also be helpful for the other discovery of new physiological role of MGP.