OSGEP Human

O-Sialoglycoprotein Endopeptidase (OSGEP) is a protein encoded by the OSGEP gene in humans. This enzyme is a part of the highly conserved KEOPS complex (Kinase, Endopeptidase, and Other Proteins of small Size), which plays a crucial role in various cellular processes, including tRNA modification and protein synthesis .

The human recombinant O-Sialoglycoprotein Endopeptidase is produced in Escherichia coli (E. coli) and is a single, non-glycosylated polypeptide chain containing 358 amino acids. It has a molecular mass of approximately 38.8 kDa. The recombinant protein is fused to a 23 amino acid His-tag at the N-terminus, which facilitates its purification through chromatographic techniques .

OSGEP is involved in the second biosynthetic step in the formation of N-6-threonylcarbamoyladenosine (t6A), a modified nucleoside found in tRNA. This modification is essential for the proper functioning of tRNA and, consequently, for accurate protein synthesis . Additionally, OSGEP has been implicated in various cellular processes, including cell proliferation and mitochondrial metabolism .

Research has shown that OSGEP plays a protective role against hepatic ischemia-reperfusion injury (HIRI), a critical complication of liver resection and transplantation. OSGEP mediates its protective effects by modulating the MEK/ERK signaling pathway, which is involved in cell survival and proliferation. Overexpression of OSGEP has been found to protect cells against ferroptotic cell death, while its deficiency exacerbates liver damage and cell death in models of HIRI .

The recombinant OSGEP protein is typically stored at -20°C for long-term storage, with the addition of a carrier protein such as human serum albumin (HSA) or bovine serum albumin (BSA) to prevent degradation. It is recommended to avoid multiple freeze-thaw cycles to maintain the protein’s stability and activity .