Two novel rat liver membrane proteins that bind advanced glycosylation endproducts: relationship to macrophage receptor for glucose-modified proteins.

作者：Zhe Yang, Zenji Makita, Yuko Horii, Serge Brunelle, Anthony Cerami, P. K. Sehajpal, Manikkam Suthanthiran, Helen Vlassara · 发表于：The Journal of Experimental Medicine · 年份：1991 · DOI：10.1084/jem.174.3.515 · 被引用次数：194 · 研究领域：Advanced Glycation End Products research、Natural Antidiabetic Agents Studies、Glycosylation and Glycoproteins Research

Advanced glycosylation endproducts (AGEs), the glucose-derived adducts that form nonenzymatically and accumulate on tissue proteins, are implicated in many chronic complications associated with diabetes and aging. We have previously described a monocyte/macrophage surface receptor system thought to coordinate AGE protein removal and tissue remodeling, and purified a corresponding 90-kD AGE-binding protein from the murine RAW 264.7 cell line. To identify AGE-binding proteins in normal animals, the tissue distribution of 125I-AGE rat serum albumin taken up from the blood was determined in rats in vivo. These uptake studies demonstrated that the liver was a major site of AGE protein sequestration. Using a solid-phase assay system involving the immobilization of solubilized membrane proteins onto nitrocellulose to monitor binding activity, and several purification steps including affinity chromatography over an AGE bovine serum albumin matrix, two rat liver membrane proteins were isolated that specifically bound AGEs, one migrating at 60 kD (p60) and the other at 90 kD (p90) on SDS-PAGE. NH2-terminal sequence analysis revealed no significant homology between these two proteins nor to any molecules available in sequence databases. Flow cytometric analyses using avian antibodies to purified rat p60 and p90 demonstrated that both proteins are present on rat monocytes and macrophages. Competition studies revealed no crossreactivity between the two antisera; anti-p60 and anti-p90 anti...