The 94- to 97-kDa mouse macrophage membrane protein that recognizes oxidized low density lipoprotein and phosphatidylserine-rich liposomes is identical to macrosialin, the mouse homologue of human CD68.

We have previously reported the partial purification of a 94- to 97-kDa plasma membrane protein from mouse peritoneal macrophages that binds oxidatively modified low density lipoprotein (OxLDL) and phosphatidylserine-rich liposomes. We have now identified that protein as macrosialin, a previously cloned macrophage-restricted membrane protein in the lysosomal-associated membrane protein family (mouse homologue of human CD68). Early in the course of purification of the 94- to 97-kDa protein, a new OxLDL-binding band at 190-200 kDa appeared and copurified with the 94- to 97-kDa protein. The HPLC pattern of tryptic peptides from this higher molecular mass ligand-binding band closely matched that derived from the 94- to 97-kDa band. Specifically, the same three macrosialin-derived tryptic peptides (9, 9, and 15 residues) were present in the purified 94- to 97-kDa band and in the 190- to 200-kDa band and antisera raised against peptide sequences in macrosialin recognized both bands. An antiserum against macrosialin precipitated most of the 94- to 97-kDa OxLDL-binding material. We conclude that the binding of OxLDL to mouse macrophage membranes is in part attributable to macrosialin. Our previous studies show that OxLDL competes with oxidized red blood cells and with apoptotic thymocytes for binding to mouse peritoneal macrophages. Whether macrosialin plays a role in recognition of OxLDL and oxidatively damaged cells by intact macrophages remains uncertain.

Análisis de las dos líneas de transmisión del tratado de Tudmīr (94 H./713 e.C.)

Los dos textos principales de las líneas de transmisión del tratado de Tudmīr (94 H/713 e.C.), incluidos por al-‘Uḏrī y al-Ḍabbī en sus respectivas obras, son editados y traducidos en base a la relectura de los manuscritos que los contienen y de ello se extraen una serie de conclusiones sobre su proceso de copia. Luego son comparados los dos textos entre sí y se enumeran una serie de diferencias textuales. Finalmente, como hipótesis interpretativa se propone que el texto de al-‘Uḏrī es el más antiguo, y habría sido copiado de un traslado del original por su autor, mientras que la transmisión de al-Ḍabbī habría sido más reciente y se habría fundado en otra fuente más antigua que habría puesto por escrito un relato oral del texto.