Characterization of the Hepatic Cellular Uptake of α1-Acid Glycoprotein (AGP), Part 1: A Peptide Moiety of Human AGP Is Recognized by the Hemoglobin β-Chain on Mouse Liver Parenchymal Cells

Molecular Aspects of Human Alpha-1 Acid Glycoprotein — Structure and Function

“…[98,99] We also clarified that AGP was mainly incorporated into liver parenchymal cells via a receptor-mediated pathway, and the hemoglobin β-chain located on liver plasma membranes contributes to the intracellular uptake of AGP. [100,101] These data suggest that AGP is finally taken up by liver parenchymal cells via the hemoglobin β-chain and is then degraded or eliminated from the body.…”

“…In order to clarify the role of glycans in the renal elimination of AGP, we prepared a recombinant glycan-deficient AGP by mutating the five Asn residues to Asp residues using a Pichia expression system and studied the pharmacokinetics of this recombinant glycan-deficient AGP in mice. [101] The glycan-deficient AGP was eliminated from the blood circulation very rapidly, due to filtration in the kidney. In addition, McCurdy et al also obtained similar results using glycan-deficient AGP in rabbits.…”

Characterization of Hepatic Cellular Uptake of α1-Acid Glycoprotein (AGP), Part 2: Involvement of Hemoglobin β-Chain on Plasma Membranes in the Uptake of Human AGP by Liver Parenchymal Cells

“…However, little information is available concerning the localization of HBA and HBB on these cells. We previously found that HBB is expressed on the surface of mice hepatocytes and HepG2 cells,22 and immunostaining analyses revealed that HBB is localized on the plasma membrane (Fig. 2).…”